First Quarter 2025 Earnings Call April 30, 2025

Forward-Looking Statements Certain statements contained in this presentation may constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. This presentation may contain “forward-looking statements” with respect to our business, results of operations and financial condition, and our expectations or beliefs concerning future events and conditions. You can identify forward-looking statements because they contain words such as, but not limited to, “believes,” “expects,” “may,” “should,” “approximately,” “anticipates,” “estimates,” “intends,” “plans,” “targets,” likely,” “will,” “would,” “could” and similar expressions (or the negative of these terminologies or expressions). All forward-looking statements involve risks and uncertainties. Many risks and uncertainties are inherent in our industry and markets, while others are more specific to our business and operations. These risks and uncertainties include, but are not limited to: market competition; economic downturn or industry specific conditions including the impacts of tax and tariff programs, inflation, foreign currency exchange, and industry consolidation; disruption to business operations; natural disasters including severe flooding and other weather-related events; the conflict between Russia and Ukraine and other geopolitical tensions; the inability to meet customer demand and quality requirements; the loss of key customers, suppliers or other business relationships; supply disruptions; excessive inflation; the capacity and effectiveness of our hedging policy activities; the loss of key employees; levels of indebtedness which could limit our operating flexibility and opportunities; and other risk factors set forth under the heading “Risk Factors” in our Annual Report on Form 10-K, and as described from time to time in subsequent reports filed with the U.S. Securities and Exchange Commission. The occurrence of the events described and the achievement of the expected results depend on many events, some or all of which are not predictable or within our control. Consequently, actual results may differ materially from the forward-looking statements contained in this press release. We undertake no obligation to update or revise any forward-looking statement as a result of new information, future events or otherwise, except as required by law. First Quarter 2025 - Earnings Call - 2

Non-GAAP Measures This presentation includes information regarding certain non-GAAP financial measures, including Adjusted EBITDA, Free Cash Flow and Net debt. These measures are presented because management uses this information to monitor and evaluate financial results and trends and believes this information to also be useful for investors. Adjusted EBITDA measures are frequently used by securities analysts, investors and other interested parties in their evaluation of Constellium and in comparison to other companies, many of which present an adjusted EBITDA-related performance measure when reporting their results. Adjusted EBITDA, Free Cash Flow and Net debt are not presentations made in accordance with U.S. GAAP and may not be comparable to similarly titled measures of other companies. These non-GAAP financial measures supplement our GAAP disclosures and should not be considered an alternative to the GAAP measures. This presentation provides a reconciliation of non-GAAP financial measures to the most directly comparable GAAP financial measures. For the definitions or Adjusted EBITDA, Free Cash Flow and Net debt, please refer to our accompanying press release. We are not able to provide a reconciliation of Adjusted EBITDA guidance to net income, the comparable GAAP measure, because certain items that are excluded from Adjusted EBITDA cannot be reasonably predicted or are not in our control. In particular, we are unable to forecast the timing or magnitude of realized and unrealized gains and losses on derivative instruments, non-cash impact of metal price lag, impairment or restructuring charges, or taxes without unreasonable efforts, and these items could significantly impact, either individually or in the aggregate, our net income in the future. First Quarter 2025 - Earnings Call - 3

Jean-Marc Germain Chief Executive Officer

Q1 2025 Highlights Safety: Recordable case rate(1) of 1.02 per million hours worked in Q1 2025 Shipments: 372 thousand tons (-2% YoY) Revenue: $2.0 billion (+5% YoY) Net income: $38 million Adjusted EBITDA: $186 million Includes positive non-cash metal price lag impact of $46 million Includes negative $10 million impact at Valais as a result of the flood Cash from Operations: $58 million Free Cash Flow: $(3) million Excludes $2 million of cash received for collection of deferred purchase price receivables Includes negative $27 million impact at Valais as the business continued to recover from the flood last year Shareholder Returns: repurchased 1.4 million shares of the Company stock for $15 million Leverage: 3.3x at March 31, 2025 Note: Segment Adjusted EBITDA excludes the non-cash impact of metal price lag. Amounts may not sum due to rounding. Solid Q1 results despite continued demand weakness across most of our end markets and the financial impact at Valais from the flood First Quarter 2025 - Earnings Call - 5 Adjusted EBITDA Bridge in $ millions (1) Recordable case rate measures the number of fatalities, serious injuries, lost-time injuries, restricted work injuries, or medical treatments per one million hours worked.

Current Assessment of Tariffs and Potential Impact on Constellium First Quarter 2025 - Earnings Call - 6 Tariffs remain a very fluid situation; we are continually monitoring and assessing the potential impact of current and future trade policies; at this stage we believe it presents opportunities for Constellium, and comes with some costs

Jack Guo Chief Financial Officer

Q1 2025 Q1 2024 % △ Shipments (kt) 51 57 (11) % Revenue ($m) 468 479 (2) % Segment Adj. EBITDA ($m) 75 87 (14) % Segment Adj. EBITDA ($ / t) 1,469 1,513 (3) % Aerospace & Transportation Q1 2025 Segment Adjusted EBITDA Bridge Q1 2025 Performance First Quarter 2025 - Earnings Call - 8 Segment Adjusted EBITDA of $75 million Lower aerospace and TID shipments Unfavorable price and mix Lower operating costs Unfavorable $4 million impact of Valais flood(1) (1) Financial impact at Valais as a result of the flood. Insurance proceeds accounted for below Adjusted EBITDA.

Q1 2025 Q1 2024 % △ Shipments (kt) 269 264 2 % Revenue ($m) 1,187 1,018 17 % Segment Adj. EBITDA ($m) 60 48 25 % Segment Adj. EBITDA ($ / t) 223 182 23 % Packaging & Automotive Rolled Products Q1 2025 Segment Adjusted EBITDA Bridge Q1 2025 Performance First Quarter 2025 - Earnings Call - 9 Segment Adjusted EBITDA of $60 million Higher packaging shipments and improved Muscle Shoals performance; lower automotive and specialty shipments Favorable price and mix Lower operating costs Unfavorable metal costs due to tighter scrap spreads in N.A.

Q1 2025 Q1 2024 % △ Shipments (kt) 52 59 (12) % Revenue ($m) 381 396 (4) % Segment Adj. EBITDA ($m) 16 32 (50) % Segment Adj. EBITDA ($ / t) 306 541 (43) % Automotive Structures & Industry Q1 2025 Segment Adjusted EBITDA Bridge Q1 2025 Performance First Quarter 2025 - Earnings Call - 10 Segment Adjusted EBITDA of $16 million Lower automotive and industry shipments Unfavorable price and mix Unfavorable $6 million impact of Valais flood(1) (1) Financial impact at Valais as a result of the flood. Insurance proceeds accounted for below Adjusted EBITDA.

Free Cash Flow of $(3) million; compared to Q1 2024: Favorable change in working capital and lower capex Lower Segment Adjusted EBITDA Excludes $2 million of cash received for collection of deferred purchase price receivables; includes $27 million flood impact at Valais Including collection of deferred purchase price receivables and excluding Valais flood impact, Q1 2025 Free Cash Flow of $26 million Repurchased 1.4 million shares for $15 million in $ millions Q1 2025 Q1 2024 Net cash flows from operating activities 58 37 Purchases of property, plant and equipment net of property, plant and equipment inflows (61) (67) Free Cash Flow (3) (30) Collection of deferred purchase price receivables 2 17 Track Record of Free Cash Flow(1) Generation in $ millions Q1 2025 Free Cash Flow Highlights Current 2025 Expectations First Quarter 2025- Earnings Call - 11 (1) Excludes $85 million, $97 million, and $90 million of cash received for collection of deferred purchase price receivables for the 2024, 2023 and 2022 periods, respectively, as a result of IFRS to U.S. GAAP conversion. >120 Free Cash Flow: >$120 million Capex: ~$330 million Cash interest: ~$120 million Cash taxes: ~$40 million TWC/Other: modest source of cash Free Cash Flow

Leverage of 3.3x at quarter-end Target leverage range of 1.5x to 2.5x No bond maturities until 2028 Strong liquidity position Debt / Liquidity Highlights Net Debt and Liquidity Maturity Profile(1) in $ millions Liquidity in $ millions Net Debt and Leverage in $ millions Strong balance sheet and improved financial flexibility give us confidence to manage varying business conditions Leverage = Net Debt / LTM Segment Adjusted EBITDA, which excludes non-cash impact of metal price lag (1) See Debt Table in the Appendix for more details First Quarter 2025- Earnings Call - 12

Jean-Marc Germain Chief Executive Officer

End Market Outlook First Quarter 2025- Earnings Call - 14 Sources: CRU International, Aluminum Rolled Products Market Outlook February 2025. Aerospace 14% of LTM revenues Packaging 41% of LTM revenues Automotive 28% of LTM revenues Other Specialties 17% of LTM revenues Current Market Trends: Demand in North America has softened Demand remains weak in Europe Tariff uncertainty Current Market Trends: Demand has stabilized at low levels in North America Demand remains weak in Europe Current Market Trends: Demand remains healthy in both North America and Europe Current Market Trends: Demand has stabilized in aviation and space; military aircraft remains healthy OEMs continue to deal with supply chain challenges SECULAR GROWTH Fuel economy Lightweighting Reduced emissions Electric vehicles Safety DIVERSIFIED CYCLES Diversified end markets with separate cycles Lightweighting in Transportation SECULAR GROWTH Sustainability Recyclability Can makers adding capacity to meet long-term demand LT SECULAR GROWTH Fuel economy Lightweighting Long-term market trends expected to remain intact CAGR (2024-2029): demand for aluminum canstock market North America: 3.1% Europe: 4.2% CAGR (2024-2029): demand for aerospace aluminum rolled product market North America + Europe: 8.2% Est. New Commercial Aircraft >42K between 2024 and 2043 CAGR (2024-2029): consumption of aluminum auto body sheet North America: 6.1% Europe: 7.8% Growth is expected to be in-line with or above gross domestic product (GDP)

Solid performance in Q1 2025 Solid Q1 results despite continued demand weakness across most of our end markets outside of packaging and the financial impact at Valais as the business continued to recover from the flood last year Remain focused on strong cost control, Free Cash Flow generation, and commercial and capital discipline Returned $15 million to shareholders through the repurchase of 1.4 million shares during the quarter Tariffs are creating uncertainty in many of our end markets, especially automotive, but we are proactively managing the business to the current environment Exciting future ahead with opportunities to grow our business and enhance profitability and returns Portfolio serving diversified and generally resilient end markets Durable, sustainability-driven secular growth trends driving increased demand for our products Infinitely recyclable aluminum is part of the circular economy Previously-indicated Adjusted EBITDA drivers within our control; market recoveries provide additional upside Execution focused with proven ability to flex costs Substantial value creation opportunities remain longer term, planting the seeds today for future growth and profitability Strong balance sheet and Free Cash Flow generation allow financial flexibility and balanced capital allocations Approximately $206 million remaining on existing share repurchase program(2)(3) Key Messages and Guidance Focused on executing our strategy and increasing shareholder value Targets (1) Excludes the non-cash impact of metal price lag. (2) Full execution of share repurchase program will require shareholder approval annually at the Annual General Meeting. (3) Expires December 31, 2026. First Quarter 2025 - Earnings Call - 15 2025 Adjusted EBITDA(1) $600 million to $630 million ——— 2025 Free Cash Flow >$120 million ——— 2028 Adjusted EBITDA(1) $900 million ——— 2028 Free Cash Flow $300 million ——— Leverage 1.5x - 2.5x

Appendix

Reconciliation of Net Income to Adjusted EBITDA ≥130 Three months ended March 31, (in millions of U.S. dollar) 2025 2024 Net income 38 22 Income tax expense 24 8 Income before tax 62 30 Finance costs - net 27 27 Expenses on factoring arrangements 5 5 Depreciation and amortization 78 75 Impairment of assets — 3 Restructuring costs 1 — Unrealized losses on derivatives 12 4 Unrealized exchange losses / (gains) from the remeasurement of monetary assets and liabilities – net 1 (2) Pension and other post-employment benefits - non - operating gains (3) (3) Share based compensation costs 6 6 Losses on disposal — 1 Other (3) — Adjusted EBITDA 186 146 of which Metal price lag (1) 46 (14) First Quarter 2025 - Earnings Call - 17 (1) Excluded in Segment Adjusted EBITDA

Three months ended March 31, (in millions of U.S. dollar) 2025 2024 Net cash flows from operating activities 58 37 Purchases of property, plant and equipment net of property, plant and equipment inflows (61) (67) Free Cash Flow (3) (30) Collection of deferred purchase price receivables 2 17 Year ended December 31, (in millions of U.S. dollar) 2024 2023 2022 Net cash flows from operating activities 301 432 365 Purchases of property, plant and equipment net of property, plant and equipment inflows (401) (365) (284) Free Cash Flow (100) 67 81 Collection of deferred purchase price receivables 85 97 90 First Quarter 2025 - Earnings Call - 18 Free Cash Flow Reconciliation

Net Debt Reconciliation ≥130 (in millions of U.S. dollar) March 31, 2025 December 31, 2024 September 30, 2024 June 30, 2024 March 31, 2024 Borrowings 1,943 1,918 1,914 1,898 1,906 Fair value of net debt derivatives, net of margin calls 1 (1) 1 — 1 Cash and cash equivalents (118) (141) (170) (228) (195) Net Debt 1,826 1,776 1,745 1,670 1,712 LTM Segment Adjusted EBITDA(1) 547 568 648 702 741 Leverage 3.3x 3.1x 2.7x 2.4x 2.3x (1) Segment Adjusted EBITDA excludes non-cash metal price lag First Quarter 2025 - Earnings Call - 19

Reconciliation of LTM Segment Adjusted EBITDA to Net Income ≥130 Twelve months ended (in millions of U.S. dollar) March 31, 2025 December 31, 2024 September 30, 2024 June 30, 2024 March 31, 2024 P&ARP 255 242 271 278 296 A&T 273 285 312 345 359 AS&I 57 74 93 110 119 H&C (38) (33) (29) (32) (33) Segment Adjusted EBITDA 547 568 648 702 741 Metal price lag 115 55 14 (12) (89) Adjusted EBITDA 663 623 662 689 653 Depreciation and amortization (307) (304) (299) (302) (301) Impairment of assets (21) (24) (21) (22) (22) Share based compensation costs (24) (25) (25) (24) (25) Pension and other post-employment benefits - non service costs 11 11 13 13 14 Restructuring costs (12) (11) (7) (3) (1) Unrealized (losses) / gains on derivatives (9) (1) 21 28 2 Unrealized exchange (losses) / gains from the remeasurement of monetary assets and liabilities – net (2) 1 (1) — (1) Losses / (gains) on disposal (4) (4) (3) 44 44 Expenses on factoring arrangements (22) (22) (23) (23) (23) Other 6 2 (10) (9) (1) Finance costs - net (112) (111) (109) (107) (111) Income before tax 168 135 200 286 229 Income tax expense (92) (76) (88) (94) (75) Net income 75 60 112 192 154 (1) Segment Adjusted EBITDA excludes non-cash metal price lag First Quarter 2025 - Earnings Call - 20

Debt Table ≥130 First Quarter 2025 - Earnings Call - 21 At March 31, At December 31, 2025 2024 (in millions of U.S. dollar) Nominal Value in Currency Nominal rate Effective rate Face Value Debt issuance costs Accrued interest Carrying value Carrying value Secured Pan-U.S. ABL (due 2029) $ 60 Floating 5.57 % 60 — — 60 56 Senior Unsecured Notes Issued June 2020 and due 2028 $ 325 5.625 % 6.05 % 325 (3) 5 327 323 Issued February 2021 and due 2029 $ 500 3.750 % 4.05 % 500 (5) 9 504 500 Issued June 2021 and due 2029 € 300 3.125 % 3.41 % 324 (3) 2 323 313 Issued August 2024 and due 2032 $ 350 6.375 % 6.77 % 350 (6) 3 347 353 Issued August 2024 and due 2032 € 300 5.375 % 5.73 % 324 (5) 3 322 313 Finance lease liabilities 30 — — 30 30 Other loans 30 — — 30 30 Total debt 1,943 (22) 22 1,943 1,918 Of which non-current 1,908 1,879 Of which current 35 39