Free cash flow margin volatility remains a concern, dropping to 4.2% in 2026Q1 from a 25.1% peak in 2025Q3 due to substantial working capital consumption of $281.7 million.
| Metric | TTM | Dec'25 | Dec'24 | Dec'23 | Dec'22 | Dec'21 | Dec'20 | Dec'19 | Dec'18 | Dec'17 | Dec'16 | Dec'15 | Dec'14 | Dec'13 | Dec'12 | Dec'11 | Dec'10 | Dec'09 | Dec'08 | Dec'07 | Dec'06 | Dec'05 | Dec'04 | Dec'03 | Dec'02 |
|---|
| Cash from Operations | 712.9M | 524.08M | -8.31M | 104.16M | -541.27M | -641.69M | -614.96M | -278.43M | -562.62M | -382.79M | -307.7M | -189.14M | -165.64M | -68.66M | -115.61M | -87.07M | -84.34M | -72.14M | 65.49M | 196.52M | -24.63M | -16.48M | -19.57M | -12.83M | -1.28M |
| Operating CF Margin % | - | 14.11% | -0.37% | 5.7% | -52.18% | -76% | -124.78% | -126.7% | -751.08% | -425.73% | -652.48% | -460.23% | -327.61% | -145.56% | -173.26% | -105.21% | -84.31% | -71.76% | 68.1% | 386.11% | -91.46% | -288.4% | -457.46% | -7288.64% | - |
| Operating CF Growth % | 1100.02% | 6405.1% | -107.98% | 119.24% | 15.65% | -4.35% | -120.87% | 50.51% | -46.98% | -24.4% | -62.68% | -14.19% | -141.26% | 40.61% | -32.78% | -3.23% | -16.9% | -210.16% | -66.67% | 897.88% | -49.41% | 15.76% | -52.56% | -903.76% | - |
| Net Income | 577.22M | 313.75M | -278.16M | -440.24M | -1.13B | -852.82M | -858.28M | -886.12M | -761.5M | -490.87M | -410.11M | -290.07M | -360.39M | -89.22M | -106.01M | -57.65M | -43.52M | -47.59M | -26.25M | -85.47M | -34.61M | -42.91M | -32.65M | -25.03M | -4.14M |
| Depreciation & Amortization | 54.81M | 55.66M | 56.67M | 97.03M | 85.55M | 89.69M | 74.44M | 54.37M | 6.43M | 13.37M | 15.13M | 19.05M | 11.93M | 10.23M | 9.04M | 5.13M | 4.94M | 5.99M | 5.73M | 4.08M | 3.81M | 3.12M | 2.44M | 838K | 36K |
| Stock-Based Compensation | 290.05M | 348.24M | 272.08M | 221.68M | 230.65M | 165.72M | 139.87M | 174.84M | 157.75M | 92.82M | 75.53M | 45.78M | 33.06M | 20.7M | 12.36M | 16.8M | 19.34M | 20.17M | 18.03M | 14.47M | 8.3M | 0 | 4.11M | 0 | 0 |
| Deferred Taxes | -2.53M | -2.2M | -106.76M | 0 | 0 | -55.7M | -54.04M | -11.29M | -3.56M | 1.89M | -6.98M | 0 | -42.29M | -2.69M | -22.39M | 3.5M | 10.74M | -5.16M | -5.5M | 1.89M | -7.92M | 0 | -4.11M | 0 | 0 |
| Other Non-Cash Items | 302.79M | 253.42M | 261.94M | 214.93M | 309.24M | 174.24M | 95.75M | -12.61M | -6.84M | 2.91M | 1.51M | 984K | 221.46M | 449K | 364K | 1.08M | 3.71M | 4.86M | 9.59M | 7.12M | 8.43M | 6.55M | 7.16M | 8.46M | 172K |
| Working Capital Changes | -509.43M | -444.78M | -214.08M | 10.76M | -35.55M | -162.82M | -12.7M | 402.38M | 45.1M | -2.9M | 17.22M | 35.12M | -29.4M | -8.12M | -8.96M | -55.93M | -79.56M | -50.41M | 63.9M | 254.42M | -2.65M | 16.76M | 3.48M | 2.91M | 2.65M |
| Change in Receivables | -462.95M | -359.96M | -86.55M | -87.94M | -45.6M | -101.8M | -56.24M | -24.24M | 15.24M | -10.67M | -15.04M | 31.64M | -35.69M | -4.14M | 1.36M | 12.65M | 0 | 0 | 843K | 0 | 0 | 243K | -310K | 0 | 0 |
| Change in Inventory | -1.06M | 8.47M | 13.59M | 18.37M | -34.14M | -26.41M | -35.43M | -32.41M | -22.64M | 0 | 0 | 0 | 3.29M | 191K | -1.81M | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Change in Payables | 229.62M | 75.07M | 91.09M | 80.84M | 191.77M | 88.24M | 117.38M | 36.61M | 15.48M | -4.94M | 10.1M | 1.68M | 8.84M | 1.83M | -1.74M | -3.51M | -3.18M | 9.9M | -1.24M | -264K | 2.09M | 0 | -615K | 0 | 0 |
| Cash from Investing | 297.02M | 436.33M | -116.84M | -336.35M | 169.35M | -273.3M | -435.52M | -417.68M | 272.94M | -290.36M | 142.59M | -321.32M | -548.81M | -130.5M | 3.37M | 81.96M | 17.84M | 14.43M | 17.94M | -277.43M | -30.05M | -40.42M | -34.59M | -3.24M | -562K |
| Capital Expenditures | -71.56M | -58.7M | -34.28M | -62.21M | -72.06M | -76.37M | -70.36M | -140.16M | -126.89M | -104.21M | -64.56M | -12.95M | -8.96M | -4.01M | -8.35M | -1.29M | -4.73M | -4.95M | -10.76M | -7.79M | -4.99M | -1.95M | -9.01M | -3.12M | -562K |
| CapEx % of Revenue | 1.67% | 1.58% | 1.52% | 3.4% | 6.95% | 9.05% | 14.28% | 63.78% | 169.39% | 115.9% | 136.89% | 31.51% | 17.72% | 8.49% | 12.51% | 1.56% | 4.73% | 4.92% | 11.19% | 15.3% | 18.51% | 34.06% | 210.52% | 1772.16% | - |
| Acquisitions | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | -25M | 0 | 0 | -81.96M | -17.84M | -10M | -100K | 2.34M | 0 | 40.42M | 0 | -121K | 0 |
| Investments | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - |
| Other Investing | 4.7M | 57.63M | 57.76M | -4.44M | -13.19M | -4.36M | -31.2M | 23M | -14.82M | 120M | -150M | -1.47M | 0 | 0 | -162K | 81.96M | 17.84M | 6.15M | 0 | -839K | 0 | -40.42M | 0 | 0 | 0 |
| Cash from Financing | -333.56M | -305.19M | 294.16M | 172.13M | 425.75M | 1.25B | 994.98M | 823.18M | 65.47M | 1.12B | 177.83M | 616.18M | 736.47M | 200.93M | 93.41M | 738K | 3.66M | 3.51M | 3.15M | 58.63M | 166.63M | 52.62M | 50.98M | 23.71M | 17.32M |
| Debt Issued (Net) | -552.65M | -546.95M | 0 | 0 | 254M | 500M | 200M | -30M | 0 | -120M | 150M | 0 | 0 | 0 | 0 | 0 | 0 | 0 | -6.76M | -2.38M | 1.74M | 194K | 5.34M | -1.1M | 0 |
| Equity Issued (Net) | 5.49M | 250.03M | 302.95M | 147.46M | 259.36M | 246.27M | 99.5M | 781.9M | 65.47M | 1.16B | 13.71M | 585.04M | 707.04M | 172.18M | 86.44M | 738K | 993K | 3.51M | 9.91M | 61.01M | 164.89M | 52.42M | 45.31M | 27.48M | 17.34M |
| Dividends Paid | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Share Repurchases | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | -3.47M | -257K | -596K | -378K | -15.99M | -1.39M | -359K | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Other Financing | 213.6M | -8.27M | -8.79M | 24.67M | -87.61M | 500.85M | 695.48M | 71.28M | 0 | 83.89M | 14.13M | 31.14M | 29.42M | 28.74M | 6.97M | 0 | 2.67M | 0 | 0 | 0 | 0 | 0 | 327K | -2.67M | -28K |
| Net Change in Cash | 690.17M | 690.15M | 153.77M | -53.67M | 46.4M | 323.11M | -50.58M | 127M | -224.2M | 451.74M | 12.72M | 105.72M | 22.01M | 1.76M | -18.82M | -4.37M | -62.87M | -54.32M | 86.64M | -22.8M | 112.2M | -4.51M | -2.92M | 7.72M | 17.32M |
| Free Cash Flow | 641.34M | 465.38M | -42.59M | 41.95M | -613.33M | -718.07M | -685.32M | -418.58M | -689.5M | -487M | -372.26M | -202.09M | -174.6M | -72.66M | -123.96M | -88.36M | -89.07M | -77.09M | 54.73M | 188.73M | -29.62M | -18.43M | -28.58M | -15.95M | -1.84M |
| FCF Margin % | 14.96% | 12.53% | -1.89% | 2.29% | -59.12% | -85.05% | -139.05% | -190.48% | -920.47% | -541.64% | -789.37% | -491.74% | -345.33% | -154.05% | -185.77% | -106.77% | -89.04% | -76.69% | 56.91% | 370.81% | -109.97% | -322.46% | -667.98% | -9060.8% | - |
| FCF Growth % | 950.75% | 1192.73% | -201.54% | 106.84% | 14.59% | -4.78% | -63.72% | 39.29% | -41.58% | -30.82% | -84.2% | -15.74% | -140.29% | 41.38% | -40.29% | 0.8% | -15.54% | -240.87% | -71% | 737.26% | -60.68% | 35.5% | -79.19% | -766.68% | - |
| FCF per Share | 4.64 | 3.46 | -0.33 | 0.34 | -5.04 | -6.06 | -5.96 | -3.83 | -6.85 | -5.38 | -4.35 | -2.41 | -2.35 | -1.18 | -2.47 | -2.08 | -2.12 | -1.85 | 1.33 | 4.88 | -0.93 | -0.84 | -2.40 | -16.92 | -5.55 |
| FCF Conversion (FCF/Net Income) | 1.11x | 1.67x | 0.03x | -0.24x | 0.48x | 0.75x | 0.72x | 0.31x | 0.74x | 0.78x | 0.75x | 0.65x | 0.46x | 0.77x | 1.09x | 1.51x | 1.94x | 1.52x | -2.49x | -2.30x | 0.71x | 0.38x | 0.60x | 0.51x | 0.31x |
| Interest Paid | 215.97M | 0 | 67.58M | 0 | 0 | 0 | 0 | 172K | 775K | 2.43M | 1.1M | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1.5M | 0 | 0 | 0 | 0 | 0 | 0 |
| Taxes Paid | 1.77M | 0 | 14.36M | 0 | 0 | 0 | 0 | 2.57M | 1.07M | 114K | 111K | 66K | 0 | 11K | 17K | 0 | 5.77M | 5.84M | 2.67M | 0 | 0 | 0 | 0 | 0 | 0 |
Regulatory pricing negotiation exposure
According to recent financial statements, Alnylam's operating cash flow to net income ratio has exhibited significant volatility, with a 0.34 reading in 2026Q1, highlighting a persistent disconnect between accounting profits and actual cash generation that warrants close scrutiny from investors evaluating the company's underlying earnings quality.
The substantial gap between net income and operating cash flow suggests that non-cash items and working capital fluctuations are heavily influencing reported profitability. Investors should monitor whether this conversion ratio stabilizes as the company moves further into its commercial maturity phase.
As reported in quarterly filings, Alnylam's free cash flow margin reached 4.2% in 2026Q1, a notable decline from the 25.1% peak observed in 2025Q3, reflecting the inherent lumpiness of milestone-driven revenue and the ongoing capital requirements of a rapidly expanding late-stage clinical pipeline.
The erratic trajectory of free cash flow suggests that the company's cash generation remains highly sensitive to the timing of collaboration payments rather than purely organic product sales. This volatility may persist until the core commercial portfolio achieves sufficient scale to consistently cover R&D and operational overhead.
Based on the company's reported figures, working capital changes exerted a significant $281.7 million drag on cash flow in 2026Q1, indicating that inventory build-up or shifts in accounts receivable are currently consuming a substantial portion of the cash generated from core operations.
This negative working capital trend suggests that the company is aggressively scaling its supply chain to support global product launches. Analysts should investigate whether this cash outflow is a temporary byproduct of geographic expansion or a structural requirement for maintaining high service levels in orphan markets.
Analysis of recent SEC filings reveals that stock-based compensation reached $70.2 million in 2026Q1, a figure that effectively offsets a large portion of the reported operating cash flow and suggests that the company's cash-based performance metrics may be flattered by significant non-cash equity dilution.
The reliance on equity-based incentives to manage cash burn appears to be a consistent feature of the company's compensation strategy. Investors should consider the impact of this dilution on long-term shareholder value, as it effectively shifts the cost of talent acquisition from the cash flow statement to the equity base.
Quick answers to the most common questions about buying ALNY stock.
Alnylam Pharmaceuticals, Inc. (ALNY) generated $524.1M in net cash from operating activities in 2025. This reflects the cash generated directly from core business operations.
Alnylam Pharmaceuticals, Inc. (ALNY) generated $465.4M in free cash flow in 2025. Free cash flow is the cash left over after capital expenditures, which can be used to pay dividends, repurchase shares, or pay down debt.
Alnylam Pharmaceuticals, Inc. (ALNY) spent $58.7M on capital expenditures in 2025. CapEx represents the cash invested in physical assets like property, plant, and equipment to maintain or grow the business.