The company exhibits a persistent free cash flow deficit, which reached -$21.8 million in 2026Q1, highlighting a heavy reliance on external financing as operating cash flow consistently tracks below net losses.
| Cash from Operations | -71.85M | -66.3M | -52.79M | -43.7M | -36.07M |
| Operating CF Margin % | - | - | - | - | - |
| Operating CF Growth % | -61.33% | -25.59% | -20.8% | -21.16% | - |
| Net Income | -85.56M | -75.27M | -61.69M | -47.26M | -40.24M |
| Depreciation & Amortization | 904K | -3.05M | 668K | 583K | 122K |
| Stock-Based Compensation | 9.97M | 12.07M | 3.71M | 2.26M | 1.69M |
| Deferred Taxes | 0 | 0 | 0 | 0 | 0 |
| Other Non-Cash Items | 5.7M | 2.61M | 7.6M | 1.5M | -400K |
| Working Capital Changes | -2.86M | -2.65M | -3.08M | -783K | 2.76M |
| Change in Receivables | 0 | 0 | 0 | 0 | 0 |
| Change in Inventory | 0 | 0 | 0 | 0 | 0 |
| Change in Payables | -2.76M | -417K | 467K | 162K | -1.51M |
| Cash from Investing | 47.27M | -118.75M | -126.91M | 27.35M | -29.26M |
| Capital Expenditures | -291K | -377K | -27K | -1.12M | -1.87M |
| CapEx % of Revenue | - | - | - | - | - |
| Acquisitions | 0 | 0 | 0 | 0 | 0 |
| Investments | - | - | - | - | - |
| Other Investing | 0 | 0 | 0 | 0 | 0 |
| Cash from Financing | 5.21M | 205.71M | 178.97M | 31K | 110.86M |
| Debt Issued (Net) | 0 | 0 | 0 | 0 | 0 |
| Equity Issued (Net) | 5.21M | 205.71M | 178.97M | 0 | 110.79M |
| Dividends Paid | 0 | 0 | 0 | 0 | 0 |
| Share Repurchases | 0 | 0 | 0 | 0 | 0 |
| Other Financing | 0 | 0 | 0 | 31K | 64K |
| Net Change in Cash | -19.37M | 20.66M | -733K | -16.32M | 45.52M |
| Free Cash Flow | -72.14M | -66.67M | -52.81M | -44.81M | -37.94M |
| FCF Margin % | - | - | - | - | - |
| FCF Growth % | -34.99% | -26.24% | -17.85% | -18.11% | - |
| FCF per Share | -1.61 | -1.67 | -1.20 | -1.02 | -0.86 |
| FCF Conversion (FCF/Net Income) | 0.84x | 0.88x | 0.86x | 0.92x | 0.90x |
| Interest Paid | 0 | 0 | 0 | 0 | 0 |
| Taxes Paid | 0 | 0 | 0 | 0 | 0 |
Clinical trial execution failure
According to the provided financial data, Sionna’s operating cash flow consistently tracks below net losses, with an OCF/NI ratio fluctuating between 0.63 and 1.00, suggesting that non-cash expenses like stock-based compensation are masking the true magnitude of the company's ongoing cash depletion.
The divergence between net income and operating cash flow indicates that the company is relying heavily on non-cash accounting adjustments to mitigate the appearance of its burn rate. Investors should monitor whether this trend persists, as the reliance on equity-based compensation to preserve cash may lead to significant future dilution.
As reported in historical financial statements, Sionna’s free cash flow has remained consistently negative, reaching a quarterly low of -$21.8 million in 2026Q1, which underscores the company's total dependence on external financing to sustain its current R&D-heavy clinical development trajectory.
The lack of positive free cash flow is expected for a pre-revenue biotech, but the widening deficit suggests that clinical trial intensity is accelerating faster than the company's ability to manage its liquidity. This trajectory implies that the current $58.5 million cash position may be exhausted within the next few quarters.
Based on the reported figures, Sionna’s working capital changes have been erratic, swinging from a $3.1 million inflow in 2024Q4 to a $2.1 million outflow in 2026Q1, reflecting the inherent instability of managing clinical trial-related payables and accruals in a pre-revenue environment.
These fluctuations suggest that the company's cash position is sensitive to the timing of vendor payments and clinical service agreements. Analysts should investigate whether these swings represent a structural shift in payment terms or merely the lumpy nature of biotech research expenditures.
As indicated by the financial statements, the company’s cash flow statement obscures the true cost of operations by excluding the impact of stock-based compensation, which reached $3.8 million in 2025Q4, effectively shifting the burden of funding from cash reserves to shareholder equity dilution.
This accounting treatment suggests that the headline cash burn figures may understate the total economic cost of the company's R&D activities. Investors should be wary of the potential for continued equity issuance to bridge the gap between current cash reserves and the next major clinical data readout.
Quick answers to the most common questions about buying SION stock.
Sionna Therapeutics, Inc. (SION) generated $-66.3M in net cash from operating activities in 2025. This reflects the cash generated directly from core business operations.
Sionna Therapeutics, Inc. (SION) reported negative free cash flow of $66.7M in 2025, indicating capital requirements exceeded cash from operations.
Sionna Therapeutics, Inc. (SION) spent $0.4M on capital expenditures in 2025. CapEx represents the cash invested in physical assets like property, plant, and equipment to maintain or grow the business.