Sigma's mine halts with a December loan due; it plans to self-fund

Sigma Lithium mines lithium at Grota do Cirilo, in the Brazilian state of Minas Gerais. It calls itself the largest maker of lithium oxide concentrate in the Americas. The material goes into batteries. [C12][C12] Press release, October 1, 2026approximately 11 km from the Barreiro Pit and 8 to 9 km from the Xuxa Pits—placing the Quilombo outside environmental impact areas of the Company’s Grota do Cirilo.Sigma Lithium press release on the temporary pause of operations, Exhibit 99.1 to Form 6-K, October 1, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004782/ex99-1.htm [C9][C9] Press release, October 1, 2026the largest producer of industrial-mineral lithium oxide concentrate in the AmericasSigma Lithium press release on the temporary pause of operations, Exhibit 99.1 to Form 6-K, October 1, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004782/ex99-1.htm In the second quarter it made 35,400 tonnes and sold 24,400 tonnes for $55 million. Its realized price, adjusted to a standard grade, was $2,089 a tonne. Its all-in sustaining cost, the full cost to keep the mine going, was $668 a tonne. [C52][C52] Second-quarter results releaseresulting from production growth to 35,400t and financial disciplineSigma Lithium second-quarter 2026 results press release, Exhibit 99.3 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-3.htm [C50][C50] Second-quarter results releaseNet revenues of US$55 million from the sale of 24,400t of lithium oxide concentrateSigma Lithium second-quarter 2026 results press release, Exhibit 99.3 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-3.htm [C51][C51] Second-quarter results releaseRealized price of US$2,089 (SC5), up by 17% from US$1,790 in 1Q 26.Sigma Lithium second-quarter 2026 results press release, Exhibit 99.3 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-3.htm [C53][C53] Second-quarter results releaseTotal Cash Costs: US$668/t (AISC - All-In Sustaining Cost)Sigma Lithium second-quarter 2026 results press release, Exhibit 99.3 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-3.htm

Second-quarter revenue of $54.7 million was a record. The adjusted EBITDA margin was 47%. [C23][C23] MD&A, financial highlightsNet sales revenue of $54.7 million, up by 3.2x on a year-over-year basis and marking the highest ever quarterly revenue.Sigma Lithium management's discussion and analysis for the six months ended June 30, 2026, Exhibit 99.1 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-1.htm [C24][C24] MD&A, financial highlightsAdjusted EBITDA margin of 47.0%, also the highest in the Company’s history.Sigma Lithium management's discussion and analysis for the six months ended June 30, 2026, Exhibit 99.1 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-1.htm EBITDA is profit before interest, taxes and some noncash costs. Sigma's adjusted figure also adds back $10 million of stock pay. [C26][C26] MD&A, EBITDA reconciliation(+) Stock-based compensation 10,004 (201) 10,319 1,216 Adjusted EBITDA 25,694 (17,077) 42,398 (5,652)Sigma Lithium management's discussion and analysis for the six months ended June 30, 2026, Exhibit 99.1 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-1.htm Under standard accounting it still lost $2.6 million in the quarter. First-half profit of $8.5 million rested on a currency gain of the same size that brought in no cash. Idle-plant costs took $17.1 million. [C25][C25] MD&A, quarterly resultsQ2 2026 Net loss of $2.6 millionSigma Lithium management's discussion and analysis for the six months ended June 30, 2026, Exhibit 99.1 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-1.htm [C4A][C4A] Statement of incomeNet income (loss) for the period (2,644) (18,859) 8,490 (14,131)Sigma Lithium interim financial statements for the six months ended June 30, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-2.htm [C4B][C4B] Note on financial resultsForeign exchange variation on net assets (2) 1,295 6,497 8,506 14,881Sigma Lithium interim financial statements for the six months ended June 30, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-2.htm [C4C][C4C] Note on other operating expensesIdle capacity (industrial plant) (1) (9,427) - (17,078) -Sigma Lithium interim financial statements for the six months ended June 30, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-2.htm

The mine has stopped before. From the week of July 17 a state agency partly suspended it and fined it about US$540,000. [C55][C55] Second-quarter results releaseSince the week started July 17, 2026, mining and plant operations have been temporarily paused as part of a partial suspensionSigma Lithium second-quarter 2026 results press release, Exhibit 99.3 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-3.htm [C66][C66] Press release, July 22, 2026issuing fines totaling approximately US$540,000.Sigma Lithium press release on negotiating a TAC agreement with Minas Gerais, Exhibit 99.1 to Form 6-K, July 22, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426003854/ex99-1.htm Sigma said operations were fully back online in August after it signed a settlement with the state, called a TAC. [C65][C65] Press release, August 2026The Company’s industrial and mining operations returned to being fully back online following the signature of a TAC Agreement.Sigma Lithium press release on full resumption of operations and the TAC agreement, Exhibit 99.1 to Form 6-K, August 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004316/ex99-1.htm

The new case was brought by Ngolo, a non-profit group, on behalf of Quilombolas, descendants of enslaved Afro-Brazilians. It asks state officials to suspend Sigma's environmental licenses. [C5][C5] Press release, October 1, 2026issued by a local Federal Court, in a lawsuit filed by Ngolo (“NGO Lawsuit”) requesting Minas Gerais state authorities to suspend the Company’s environmental licensesSigma Lithium press release on the temporary pause of operations, Exhibit 99.1 to Form 6-K, October 1, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004782/ex99-1.htm [C8][C8] Press release, October 1, 2026Sigma Lithium’s legal defense technically demonstrates that the Company's distance to the houses of Quilombolas (descendants of enslaved Afro-Brazilians living in rural settlements) is further than legal limitsSigma Lithium press release on the temporary pause of operations, Exhibit 99.1 to Form 6-K, October 1, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004782/ex99-1.htm The fight is over distance. Sigma says the homes are about 11 km from one pit and 8 to 9 km from others. The suit uses 2.7 km, from a newer boundary that Sigma says is far too big. [C12][C12] Press release, October 1, 2026approximately 11 km from the Barreiro Pit and 8 to 9 km from the Xuxa Pits—placing the Quilombo outside environmental impact areas of the Company’s Grota do Cirilo.Sigma Lithium press release on the temporary pause of operations, Exhibit 99.1 to Form 6-K, October 1, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004782/ex99-1.htm [C13][C13] Press release, October 1, 2026The 2.7 km distance falsely claimed by the Ngolo Lawsuit stems solely from this new self-proclaimed RTID perimeter containing an anomalous measurement 30x larger than the original baselineSigma Lithium press release on the temporary pause of operations, Exhibit 99.1 to Form 6-K, October 1, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004782/ex99-1.htm

A statement from a lawmaker's office says the court order came on September 4. It says the state agency later suspended five of Sigma's licenses. It also says two lawmakers filed a criminal complaint claiming Sigma kept mining in defiance of the order, in case No. 6012059-96.2026.4.06.3816. [C81][C81] Statement from a federal deputy's office, September 25, 2026This regulatory action complies with a Federal Court injunction issued on September 4th, which nullified the environmental licenses and mandated a total halt to all extraction and pit activities at the site (Civil Public Action No. 6012059-96.2026.4.06.3816/MG).PR Newswire · Read October 2, 2026Open source ↗https://www.prnewswire.com/news-releases/brazilian-congresswoman-applauds-suspension-of-sigma-lithiums-environmental-permits-302890396.html [C80][C80] Statement from a federal deputy's office, September 25, 2026Federal Deputy Célia Xakriabá publicly welcomed the Minas Gerais state government's decision this Thursday (24th) to suspend five environmental operating licenses held by Sigma Lithium.PR Newswire · Read October 2, 2026Open source ↗https://www.prnewswire.com/news-releases/brazilian-congresswoman-applauds-suspension-of-sigma-lithiums-environmental-permits-302890396.html [C82][C82] Statement from a federal deputy's office, September 25, 2026Last week, Deputy Xakriabá and fellow Federal Deputy Duda Salabert filed a formal criminal complaint with the Federal Public Prosecutor's Office (MPF) and the Federal Police. The filing demands urgent intervention amid substantial evidence that Sigma unlawfully maintained mining operations at the Grota do Cirilo project in direct defiance of the federal injunction.PR Newswire · Read October 2, 2026Open source ↗https://www.prnewswire.com/news-releases/brazilian-congresswoman-applauds-suspension-of-sigma-lithiums-environmental-permits-302890396.html Sigma told investors on September 8 and again later that month that its operations continued. On September 28 it said the agency's act had no legal validity while the case was under review. [C60][C60] Press release, September 8, 2026Sigma Lithium confirms that its mining and industrial activities continue to operateSigma Lithium press release saying operations remain unaffected by a preliminary ruling, Exhibit 99.1 to Form 6-K, September 8, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004491/ex99-1.htm [C62][C62] Press release, September 2026Sigma Lithium confirms that its mining and industrial operations continue normally.Sigma Lithium press release on Climate Week saying operations continue normally, Exhibit 99.1 to Form 6-K, September 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004580/ex99-1.htm [C63][C63] Press release, September 28, 2026the administrative act published by FEAM, as the state’s executive branch of power, has no legal validity, given that the matter remains submitted for the evaluation of the Federal Judiciary Power and there is still no definitive decision on the case.Sigma Lithium press release on the state agency's act, Exhibit 99.1 to Form 6-K, September 28, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004722/ex99-1.htm

On September 30 Sigma stopped all mining and plant production. It got FEAM's notice the evening before. It blames a federal appeals court that took 15 days without ruling on its defense. [C1][C1] Press release, October 1, 2026announces that all of its mining and industrial production was temporarily suspended yesterday, on September 30.Sigma Lithium press release on the temporary pause of operations, Exhibit 99.1 to Form 6-K, October 1, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004782/ex99-1.htm [C11][C11] Press release, October 1, 2026the Company received and acknowledged in the evening of September 29 an electronic notification posted by FEAM, in legal conformity with the environmental process of Minas Gerais.Sigma Lithium press release on the temporary pause of operations, Exhibit 99.1 to Form 6-K, October 1, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004782/ex99-1.htm [C2][C2] Press release, October 1, 2026The suspension is a result of an atypical 15-day delay by the Federal Court of Appeals in reviewing the Company’s legal defenseSigma Lithium press release on the temporary pause of operations, Exhibit 99.1 to Form 6-K, October 1, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004782/ex99-1.htm It now pushes back its 12-month goal of 240,000 tonnes by three months, and it keeps its 2027 goal of 330,000 tonnes. Those are targets, not results. [C3][C3] Press release, October 1, 2026expecting to deliver 330,000t of lithium oxide concentrate in FY 27. However, the Company will postpone by 3 months its 12-month guidance of 240,000t.Sigma Lithium press release on the temporary pause of operations, Exhibit 99.1 to Form 6-K, October 1, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004782/ex99-1.htm

Sigma gives no cost for the halt. It made 35,400 tonnes in the second quarter, or about 11,800 a month. At $2,089 a tonne, each lost month is worth roughly $25 million. [C52][C52] Second-quarter results releaseresulting from production growth to 35,400t and financial disciplineSigma Lithium second-quarter 2026 results press release, Exhibit 99.3 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-3.htm [C51][C51] Second-quarter results releaseRealized price of US$2,089 (SC5), up by 17% from US$1,790 in 1Q 26.Sigma Lithium second-quarter 2026 results press release, Exhibit 99.3 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-3.htm

Most of Sigma's short-term debt is a $100 million loan from Synergy, signed in 2022. Sigma books it as an export prepayment. It pays interest at a benchmark rate plus 6.95 points and matures on December 13, 2026. [C41][C41] Note on loans and export prepaymentsOn December 13, 2022, the Company, through Sigma Brazil, entered into an export prepayment agreement in the amount of $100,000, with annual interest payments based on the 12-month Bloomberg short-term bank yield index (“BSBY”) plus 6.95% per annum and maturing on December 13, 2026.Sigma Lithium interim financial statements for the six months ended June 30, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-2.htm [C42][C42] Note on loans and export prepaymentsFor interest payments after December 2024, the applicable rate applied is SOFR + 6.95%.Sigma Lithium interim financial statements for the six months ended June 30, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-2.htm At June 30 it stood at $105.9 million, or $94.6 million after $11.3 million of cash held as collateral. It is secured on Sigma's assets, licenses and the shares of its Brazilian unit. It ranks ahead of nearly all other debt. [C40][C40] Note on loans and export prepaymentsExport prepayment trade finance 14,042 24,140 - - Export prepayment agreement - Synergy 105,850 100,617Sigma Lithium interim financial statements for the six months ended June 30, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-2.htm [C46][C46] Note on loans and export prepaymentsThe net amount payable to settle the export prepayment (Synergy) should be offset against the $11,253 cash held as collateral, as disclosed in note 8. As of June 30, the net amount of the export prepayment (Synergy) is $94,597Sigma Lithium interim financial statements for the six months ended June 30, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-2.htm [C45][C45] Note on loans and export prepaymentsThe loan is guaranteed by the Company's assets, rights, licenses, receivables, contracts (with flexibility to enter/terminate/amend offtake agreements) and a pledge of 100% of Sigma Lithium Holdings Inc’s share interest in Sigma Brazil. Security will rank first in respect to all existing and future indebtedness of the Company, except in relation to permitted indebtedness of up to $100,000 and R$100,000.Sigma Lithium interim financial statements for the six months ended June 30, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-2.htm

Synergy is also repaid early out of cash flow. A payment is due 48 days after each March 31 and September 30. It equals half the cash from operations and investing in the six months before. [C43][C43] Note on loans and export prepaymentsprincipal repayments are due 48 days after the end of the Company’s first and third quarters ending March 31 and September 30, respectively, each yearSigma Lithium interim financial statements for the six months ended June 30, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-2.htm [C44][C44] Note on loans and export prepaymentsRepayments are based on an amount equivalent to 50% of the Company’s net cash generated from operating activities plus 50% of the net cash generated from investing activities for the prior six-month period ending March 31 and September 30.Sigma Lithium interim financial statements for the six months ended June 30, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-2.htm Another $14.0 million of short-term debt is trade finance. [C40][C40] Note on loans and export prepaymentsExport prepayment trade finance 14,042 24,140 - - Export prepayment agreement - Synergy 105,850 100,617Sigma Lithium interim financial statements for the six months ended June 30, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-2.htm Sigma also owed suppliers $60.5 million in June, though it disputes $29.6 million of that. [C33][C33] MD&A, contractual obligationsAs of June 30, 2026, out of the total $60,459 due to suppliers, $29,603 (49.4%) relates to amounts disputed by the CompanySigma Lithium management's discussion and analysis for the six months ended June 30, 2026, Exhibit 99.1 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-1.htm

Leases add $132.1 million, with $42.4 million due within a year. Most is mining gear leased for four years at a 15.03% interest rate. Those payments run on while the fleet sits idle. [C47][C47] Note on lease liabilityLease liability total 132,128 2,801 Current 42,371 1,214Sigma Lithium interim financial statements for the six months ended June 30, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-2.htm [C48][C48] Note on lease liabilitythe Company entered into and recognized a lease agreement for operational material handling equipment with a lease term of four years and an implicit interest rate of 15.03%.Sigma Lithium interim financial statements for the six months ended June 30, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-2.htm

At June 30 Sigma had negative working capital of $175.7 million. That means bills due within a year far topped its short-term assets. [C20][C20] MD&A, operations and liquidityAs of June 30, 2026, the Company reported negative working capital of $175.7 million which may cast significant doubt on the Company’s ability to continue as a going concern as of that date.Sigma Lithium management's discussion and analysis for the six months ended June 30, 2026, Exhibit 99.1 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-1.htm Its report said that may cast significant doubt on its ability to continue as a going concern. That means its ability to keep running and paying its bills. [C20][C20] MD&A, operations and liquidityAs of June 30, 2026, the Company reported negative working capital of $175.7 million which may cast significant doubt on the Company’s ability to continue as a going concern as of that date.Sigma Lithium management's discussion and analysis for the six months ended June 30, 2026, Exhibit 99.1 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-1.htm Managers said they were comfortable because of recent results and cash flow. That cash flow now depends on a restart. [C22][C22] MD&A, operations and liquiditybased on the Company s recent operating performance and cash flow generation, management is comfortable with the Company s ability to continue operating as a going concernSigma Lithium management's discussion and analysis for the six months ended June 30, 2026, Exhibit 99.1 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-1.htm

Sigma says it will keep selling high-purity lithium fines, made from tailings left by past production, to fund itself. Fines brought in about $45.0 million of revenue in the first half. [C4][C4] Press release, October 1, 2026Sigma Lithium will maintain the commercial and recycling operations that ensure the circularity of 100% of its dry stacked tailings, selling high-purity lithium fines, generating cash flow and expecting to continue to self-fund the Company during the temporary suspension.Sigma Lithium press release on the temporary pause of operations, Exhibit 99.1 to Form 6-K, October 1, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004782/ex99-1.htm [C32][C32] MD&A, operations and liquidityOperations related to the sale of high-purity lithium fines, consisting of tailings generated by previous production, have continued without disruption.Sigma Lithium management's discussion and analysis for the six months ended June 30, 2026, Exhibit 99.1 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-1.htm [C31][C31] MD&A, operations and liquiditythe Company recognized net revenue of approximately $45.0 million as a result of the sale of low-grade material (high-purity lithium fines).Sigma Lithium management's discussion and analysis for the six months ended June 30, 2026, Exhibit 99.1 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-1.htm But the fines stock carried on its books fell from $7.7 million at year-end to zero by June. Sigma gives no tonnage or price for what is left to sell. [C49][C49] Note on inventoriesHigh purity lithium fines - 7,690Sigma Lithium interim financial statements for the six months ended June 30, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-2.htm

Buyers have also paid ahead. A December 2025 deal for 70,500 tonnes in 2026 pays Sigma $96 million, at $8 million a month. Sigma says both its long-term supply deals, called offtakes, allow flexible delivery dates. [C27][C27] MD&A, operations and liquidityIn December 2025, the Company signed an offtake agreement for 70,500 tonnes of high grade lithium oxide concentrate to be supplied during 2026. This agreement provides a working capital revolver of $96.0 million to be disbursed in fixed monthly installments of $8.0 million.Sigma Lithium management's discussion and analysis for the six months ended June 30, 2026, Exhibit 99.1 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-1.htm [C69][C69] Press release, March 30, 2026Both agreements include flexibility regarding the timing of delivery of the productSigma Lithium press release on its 2025 results and offtake agreements, Exhibit 99.1 to Form 6-K, March 30, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426001884/ex99-1.htm A March deal for 120,000 tonnes over three years included a $50 million advance due by the end of June. Customer advances at June 30 were only $15.7 million. So the filings do not show that the advance came in. [C68][C68] First-quarter financial statements, note 1signed a three-year long-term offtake agreement for 40,000 tonnes per year of high-grade lithium oxide concentrate to be supplied over a three-year period, totaling 120,000 tonnes, which includes an advance payment of $50 million payable by the end of June 2026.Sigma Lithium interim financial statements for the three months ended March 31, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426003065/ex99-2.htm [C4D][C4D] Note on customer prepaymentsAs of June 30, 2026, the Company had $15,651 ($5,062 as of December 31, 2025) in customer advances related to export contracts for the future delivery of products.Sigma Lithium interim financial statements for the six months ended June 30, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-2.htm

In August Sigma said it was negotiating new financing to prepay Synergy and was weighing a range of options. Nothing has been announced since, and its report says it may issue new shares to adjust its capital. [C54][C54] Second-quarter results releaseNegotiations to secure financing for the repayment of amounts outstanding under the export prepayment agreement with Synergy, which totaled US$95 million as of June 30, 2026 (excluding $11 million cash held as collateral), are expected to enable a pre-payment. Sigma Lithium is currently evaluating a range of financing alternativesSigma Lithium second-quarter 2026 results press release, Exhibit 99.3 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-3.htm [C4F][C4F] Note on capital managementIn order to maintain or adjust its capital structure, the Company may issue new shares in the form of private placements and/or public offerings.Sigma Lithium interim financial statements for the six months ended June 30, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-2.htm One shareholder already owns 42.49% of the stock. There are 112,568,313 shares, or 113,308,506 counting stock units and options. [C29][C29] MD&A, risk factorsThe Company has a minority shareholder which owns 42.49% of the outstanding Common SharesSigma Lithium management's discussion and analysis for the six months ended June 30, 2026, Exhibit 99.1 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-1.htm [C28][C28] MD&A, current share dataCommon shares issued and outstanding 112,568,313 RSUs 612,068 Stock options 128,125 Fully diluted number of common shares 113,308,506Sigma Lithium management's discussion and analysis for the six months ended June 30, 2026, Exhibit 99.1 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-1.htm

Net debt, which is debt minus cash, was $119.4 million at June 30. That is about 1.4 times a year of first-half adjusted EBITDA, or about 3.0 times counting leases. [C21][C21] MD&A, liquidityAs of June 30, 2026, the Company’s cash and cash equivalents totaled $16.7 million. Total debt was $136.1 million and short term debt was $123.4 million, mostly comprised of $119.9 million in export prepayments. Net debt stood at $119.4 million.Sigma Lithium management's discussion and analysis for the six months ended June 30, 2026, Exhibit 99.1 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-1.htm [C26][C26] MD&A, EBITDA reconciliation(+) Stock-based compensation 10,004 (201) 10,319 1,216 Adjusted EBITDA 25,694 (17,077) 42,398 (5,652)Sigma Lithium management's discussion and analysis for the six months ended June 30, 2026, Exhibit 99.1 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-1.htm [C47][C47] Note on lease liabilityLease liability total 132,128 2,801 Current 42,371 1,214Sigma Lithium interim financial statements for the six months ended June 30, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-2.htm Interest was already heavy. In the second quarter, net finance costs of $7.5 million nearly matched operating income of $7.6 million, and with no output that cushion is gone. [C4G][C4G] Statement of incomeOperating income (loss) before financial results and income taxes 7,568 (20,158) 21,353 (13,368) Financial income (expenses), net 25 (7,498) 1,299 (5,864) 4,237Sigma Lithium interim financial statements for the six months ended June 30, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-2.htm

The stock fell about 11% on October 1, the day of the announcement, to $8.335. Albemarle, a large lithium producer, fell about 0.8%, and LIT, a lithium fund, fell about 0.5%. [C90][C90] IEX closing pricesSGML closed at $9.41 on September 30, 2026 (IEX)IEX closing prices for SGML, ALB and LIT, September 15 to October 1, 2026Open source ↗https://iextrading.com/trading/market-data/ [C91][C91] IEX closing pricesSGML closed at $8.335 on October 1, 2026 (IEX)IEX closing prices for SGML, ALB and LIT, September 15 to October 1, 2026Open source ↗https://iextrading.com/trading/market-data/ [C92][C92] IEX closing pricesALB closed at $105.8 on September 30, 2026 (IEX)IEX closing prices for SGML, ALB and LIT, September 15 to October 1, 2026Open source ↗https://iextrading.com/trading/market-data/ [C93][C93] IEX closing pricesALB closed at $104.98 on October 1, 2026 (IEX)IEX closing prices for SGML, ALB and LIT, September 15 to October 1, 2026Open source ↗https://iextrading.com/trading/market-data/ [C94][C94] IEX closing pricesLIT closed at $68.42 on September 30, 2026 (IEX)IEX closing prices for SGML, ALB and LIT, September 15 to October 1, 2026Open source ↗https://iextrading.com/trading/market-data/ [C95][C95] IEX closing pricesLIT closed at $68.1 on October 1, 2026 (IEX)IEX closing prices for SGML, ALB and LIT, September 15 to October 1, 2026Open source ↗https://iextrading.com/trading/market-data/ At that price Sigma's shares were worth about $938 million. Our price records start September 15, when it closed at $9.105. [C28][C28] MD&A, current share dataCommon shares issued and outstanding 112,568,313 RSUs 612,068 Stock options 128,125 Fully diluted number of common shares 113,308,506Sigma Lithium management's discussion and analysis for the six months ended June 30, 2026, Exhibit 99.1 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-1.htm [C91][C91] IEX closing pricesSGML closed at $8.335 on October 1, 2026 (IEX)IEX closing prices for SGML, ALB and LIT, September 15 to October 1, 2026Open source ↗https://iextrading.com/trading/market-data/ [C96][C96] IEX closing pricesSGML closed at $9.105 on September 15, 2026 (IEX)IEX closing prices for SGML, ALB and LIT, September 15 to October 1, 2026Open source ↗https://iextrading.com/trading/market-data/

Add net debt and leases, and the business is valued at about $1.19 billion. That is about 14 times a year of first-half adjusted EBITDA, a price that assumes the mine restarts. [C28][C28] MD&A, current share dataCommon shares issued and outstanding 112,568,313 RSUs 612,068 Stock options 128,125 Fully diluted number of common shares 113,308,506Sigma Lithium management's discussion and analysis for the six months ended June 30, 2026, Exhibit 99.1 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-1.htm [C91][C91] IEX closing pricesSGML closed at $8.335 on October 1, 2026 (IEX)IEX closing prices for SGML, ALB and LIT, September 15 to October 1, 2026Open source ↗https://iextrading.com/trading/market-data/ [C21][C21] MD&A, liquidityAs of June 30, 2026, the Company’s cash and cash equivalents totaled $16.7 million. Total debt was $136.1 million and short term debt was $123.4 million, mostly comprised of $119.9 million in export prepayments. Net debt stood at $119.4 million.Sigma Lithium management's discussion and analysis for the six months ended June 30, 2026, Exhibit 99.1 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-1.htm [C47][C47] Note on lease liabilityLease liability total 132,128 2,801 Current 42,371 1,214Sigma Lithium interim financial statements for the six months ended June 30, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-2.htm [C26][C26] MD&A, EBITDA reconciliation(+) Stock-based compensation 10,004 (201) 10,319 1,216 Adjusted EBITDA 25,694 (17,077) 42,398 (5,652)Sigma Lithium management's discussion and analysis for the six months ended June 30, 2026, Exhibit 99.1 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-1.htm

Sigma's goals are 330,000 tonnes in 2027 and a second phase that would lift capacity to 580,000 tonnes a year. These goals move: in August it said it had moved its 240,000-tonne target forward by a quarter, and now it pushes it back by three months. [C3][C3] Press release, October 1, 2026expecting to deliver 330,000t of lithium oxide concentrate in FY 27. However, the Company will postpone by 3 months its 12-month guidance of 240,000t.Sigma Lithium press release on the temporary pause of operations, Exhibit 99.1 to Form 6-K, October 1, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004782/ex99-1.htm [C14][C14] Press release, October 1, 2026The Company plans to resume in 2027 a Phase 2 expansion designed to close to double annual production capacity to 580,000 tonnesSigma Lithium press release on the temporary pause of operations, Exhibit 99.1 to Form 6-K, October 1, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004782/ex99-1.htm [C56][C56] Second-quarter results releaseSigma Lithium has moved forward by a quarter its twelve-month production guidance of 240,000 tonnes of lithium oxide concentrate.Sigma Lithium second-quarter 2026 results press release, Exhibit 99.3 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-3.htm

Lithium prices helped this year, and Sigma's realized price rose 17% from the first quarter to the second. A J.P. Morgan view that Sigma quotes puts the mine in the lowest-cost quarter of world supply. [C51][C51] Second-quarter results releaseRealized price of US$2,089 (SC5), up by 17% from US$1,790 in 1Q 26.Sigma Lithium second-quarter 2026 results press release, Exhibit 99.3 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-3.htm [C64][C64] Press release, September 2026Sigma sits in the first quartile of the cost curve (above Greenbushes but below most Australian and marginal global supply)Sigma Lithium press release on J.P. Morgan's coverage, Exhibit 99.1 to Form 6-K, September 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004627/ex99-1.htm

The bull case is a mine in the lowest-cost quarter of world supply that earned a record margin when it ran. Sigma has also won in court before, when a state appeals judge overturned a ruling against it in June. [C64][C64] Press release, September 2026Sigma sits in the first quartile of the cost curve (above Greenbushes but below most Australian and marginal global supply)Sigma Lithium press release on J.P. Morgan's coverage, Exhibit 99.1 to Form 6-K, September 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004627/ex99-1.htm [C24][C24] MD&A, financial highlightsAdjusted EBITDA margin of 47.0%, also the highest in the Company’s history.Sigma Lithium management's discussion and analysis for the six months ended June 30, 2026, Exhibit 99.1 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-1.htm [C67][C67] Press release, June 2026A Court of Appeal Judge in the Court of Justice of Minas Gerais state overturned a local lower court decision that included the potential for a legal collateral of US$10 million.Sigma Lithium press release on its state court win, Exhibit 99.1 to Form 6-K, June 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426003377/ex99-1.htm A quick win on appeal could restart the mine in time to refinance Synergy before the loan comes due. [C41][C41] Note on loans and export prepaymentsOn December 13, 2022, the Company, through Sigma Brazil, entered into an export prepayment agreement in the amount of $100,000, with annual interest payments based on the 12-month Bloomberg short-term bank yield index (“BSBY”) plus 6.95% per annum and maturing on December 13, 2026.Sigma Lithium interim financial statements for the six months ended June 30, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-2.htm

The bear case, which we rank as the bigger risk, is the calendar. Cash was thin, the loan comes due in weeks, and Sigma itself warns the ruling may be delayed. [C21][C21] MD&A, liquidityAs of June 30, 2026, the Company’s cash and cash equivalents totaled $16.7 million. Total debt was $136.1 million and short term debt was $123.4 million, mostly comprised of $119.9 million in export prepayments. Net debt stood at $119.4 million.Sigma Lithium management's discussion and analysis for the six months ended June 30, 2026, Exhibit 99.1 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-1.htm [C41][C41] Note on loans and export prepaymentsOn December 13, 2022, the Company, through Sigma Brazil, entered into an export prepayment agreement in the amount of $100,000, with annual interest payments based on the 12-month Bloomberg short-term bank yield index (“BSBY”) plus 6.95% per annum and maturing on December 13, 2026.Sigma Lithium interim financial statements for the six months ended June 30, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-2.htm [C6][C6] Press release, October 1, 2026The second round of Brazil’s general elections will be concluded on October 25. Therefore, despite its strong technical legal defense based on the rule of law and quantitative evidence, supported by maps and data, the Company believes that there is a potential scenario of a delayed legal decision by the Federal Court of Appeals.Sigma Lithium press release on the temporary pause of operations, Exhibit 99.1 to Form 6-K, October 1, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004782/ex99-1.htm If it loses, it says it will appeal to higher federal courts, which could take months. Its stand in September, that the state agency's act had no legal validity, was overtaken by the halt on September 30. [C7][C7] Press release, October 1, 2026In the event of a negative ruling by the Federal Court of Appeals, the Company will continue to follow the rule of law and seek a secondary appeal in the superior federal courtsSigma Lithium press release on the temporary pause of operations, Exhibit 99.1 to Form 6-K, October 1, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004782/ex99-1.htm [C63][C63] Press release, September 28, 2026the administrative act published by FEAM, as the state’s executive branch of power, has no legal validity, given that the matter remains submitted for the evaluation of the Federal Judiciary Power and there is still no definitive decision on the case.Sigma Lithium press release on the state agency's act, Exhibit 99.1 to Form 6-K, September 28, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004722/ex99-1.htm [C1][C1] Press release, October 1, 2026announces that all of its mining and industrial production was temporarily suspended yesterday, on September 30.Sigma Lithium press release on the temporary pause of operations, Exhibit 99.1 to Form 6-K, October 1, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004782/ex99-1.htm

Watch four dates. The runoff, which Sigma now dates October 25, comes first, and a Synergy payment is due 48 days after September 30. Then come third-quarter results and the loan's maturity. [C6][C6] Press release, October 1, 2026The second round of Brazil’s general elections will be concluded on October 25. Therefore, despite its strong technical legal defense based on the rule of law and quantitative evidence, supported by maps and data, the Company believes that there is a potential scenario of a delayed legal decision by the Federal Court of Appeals.Sigma Lithium press release on the temporary pause of operations, Exhibit 99.1 to Form 6-K, October 1, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004782/ex99-1.htm [C43][C43] Note on loans and export prepaymentsprincipal repayments are due 48 days after the end of the Company’s first and third quarters ending March 31 and September 30, respectively, each yearSigma Lithium interim financial statements for the six months ended June 30, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-2.htm [C41][C41] Note on loans and export prepaymentsOn December 13, 2022, the Company, through Sigma Brazil, entered into an export prepayment agreement in the amount of $100,000, with annual interest payments based on the 12-month Bloomberg short-term bank yield index (“BSBY”) plus 6.95% per annum and maturing on December 13, 2026.Sigma Lithium interim financial statements for the six months ended June 30, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-2.htm Our call is that the third-quarter report will again raise doubt about Sigma's ability to keep going. It is wrong if the mine restarts and Synergy is refinanced before that report, so the warning is dropped. [C20][C20] MD&A, operations and liquidityAs of June 30, 2026, the Company reported negative working capital of $175.7 million which may cast significant doubt on the Company’s ability to continue as a going concern as of that date.Sigma Lithium management's discussion and analysis for the six months ended June 30, 2026, Exhibit 99.1 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-1.htm

How much cash Sigma has now, and how fast it is spending it during the halt. The latest figure is $16.7 million at June 30. [C21][C21] MD&A, liquidityAs of June 30, 2026, the Company’s cash and cash equivalents totaled $16.7 million. Total debt was $136.1 million and short term debt was $123.4 million, mostly comprised of $119.9 million in export prepayments. Net debt stood at $119.4 million.Sigma Lithium management's discussion and analysis for the six months ended June 30, 2026, Exhibit 99.1 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-1.htm

Whether Synergy will extend or refinance its loan, and how big the payment due after September 30 will be. In August Sigma said it was negotiating financing to prepay it. [C43][C43] Note on loans and export prepaymentsprincipal repayments are due 48 days after the end of the Company’s first and third quarters ending March 31 and September 30, respectively, each yearSigma Lithium interim financial statements for the six months ended June 30, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-2.htm [C54][C54] Second-quarter results releaseNegotiations to secure financing for the repayment of amounts outstanding under the export prepayment agreement with Synergy, which totaled US$95 million as of June 30, 2026 (excluding $11 million cash held as collateral), are expected to enable a pre-payment. Sigma Lithium is currently evaluating a range of financing alternativesSigma Lithium second-quarter 2026 results press release, Exhibit 99.3 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-3.htm

Whether the halt or the license suspension counts as a default under the Synergy loan, the equipment lease or the supply deals. Sigma said it met all its debt covenants at June 30. [C4E][C4E] Note on loans and export prepaymentsAs of June 30, 2026 the Company was in compliance with all debt covenants.Sigma Lithium interim financial statements for the six months ended June 30, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-2.htm

Whether the $50 million advance under the March supply deal was paid. [C68][C68] First-quarter financial statements, note 1signed a three-year long-term offtake agreement for 40,000 tonnes per year of high-grade lithium oxide concentrate to be supplied over a three-year period, totaling 120,000 tonnes, which includes an advance payment of $50 million payable by the end of June 2026.Sigma Lithium interim financial statements for the three months ended March 31, 2026, Exhibit 99.2 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426003065/ex99-2.htm

How many tonnes of fines Sigma can still sell, at what price, and whether the license suspension covers those sales. [C4][C4] Press release, October 1, 2026Sigma Lithium will maintain the commercial and recycling operations that ensure the circularity of 100% of its dry stacked tailings, selling high-purity lithium fines, generating cash flow and expecting to continue to self-fund the Company during the temporary suspension.Sigma Lithium press release on the temporary pause of operations, Exhibit 99.1 to Form 6-K, October 1, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004782/ex99-1.htm [C32][C32] MD&A, operations and liquidityOperations related to the sale of high-purity lithium fines, consisting of tailings generated by previous production, have continued without disruption.Sigma Lithium management's discussion and analysis for the six months ended June 30, 2026, Exhibit 99.1 to Form 6-KOpen exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004250/ex99-1.htm

When the Federal Court of Appeals will rule on Sigma's emergency motion, and which judge has the case. Sigma calls the delay atypical but gives no date. [C2][C2] Press release, October 1, 2026The suspension is a result of an atypical 15-day delay by the Federal Court of Appeals in reviewing the Company’s legal defenseSigma Lithium press release on the temporary pause of operations, Exhibit 99.1 to Form 6-K, October 1, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004782/ex99-1.htm [C6][C6] Press release, October 1, 2026The second round of Brazil’s general elections will be concluded on October 25. Therefore, despite its strong technical legal defense based on the rule of law and quantitative evidence, supported by maps and data, the Company believes that there is a potential scenario of a delayed legal decision by the Federal Court of Appeals.Sigma Lithium press release on the temporary pause of operations, Exhibit 99.1 to Form 6-K, October 1, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004782/ex99-1.htm

Whether Brazil's runoff is October 25, as the October 1 release says, or November 15, as the September 8 release said. [C6][C6] Press release, October 1, 2026The second round of Brazil’s general elections will be concluded on October 25. Therefore, despite its strong technical legal defense based on the rule of law and quantitative evidence, supported by maps and data, the Company believes that there is a potential scenario of a delayed legal decision by the Federal Court of Appeals.Sigma Lithium press release on the temporary pause of operations, Exhibit 99.1 to Form 6-K, October 1, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004782/ex99-1.htm [C61][C61] Press release, September 8, 2026Brazil is entering the final weeks leading up to the second round of its general election on November 15Sigma Lithium press release saying operations remain unaffected by a preliminary ruling, Exhibit 99.1 to Form 6-K, September 8, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004491/ex99-1.htm

Whether Sigma faces penalties for operating in September while the order stood. Sigma said on September 28 that the agency's act had no legal validity. [C63][C63] Press release, September 28, 2026the administrative act published by FEAM, as the state’s executive branch of power, has no legal validity, given that the matter remains submitted for the evaluation of the Federal Judiciary Power and there is still no definitive decision on the case.Sigma Lithium press release on the state agency's act, Exhibit 99.1 to Form 6-K, September 28, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004722/ex99-1.htm

How far the stock has fallen since before the September 4 order, and how many shares are sold short. Our price records start September 15, at $9.105. [C96][C96] IEX closing pricesSGML closed at $9.105 on September 15, 2026 (IEX)IEX closing prices for SGML, ALB and LIT, September 15 to October 1, 2026Open source ↗https://iextrading.com/trading/market-data/

How fast the mine could restart after a court win, and what happens to workers meanwhile. Sigma's only hint is that it pushed its 240,000-tonne goal back three months. [C3][C3] Press release, October 1, 2026expecting to deliver 330,000t of lithium oxide concentrate in FY 27. However, the Company will postpone by 3 months its 12-month guidance of 240,000t.Sigma Lithium press release on the temporary pause of operations, Exhibit 99.1 to Form 6-K, October 1, 2026Open exact filing on SEC EDGAR ↗https://www.sec.gov/Archives/edgar/data/1848309/000129281426004782/ex99-1.htm