Cash burn remains a critical concern, as evidenced by the consistent negative free cash flow that peaked at $7.3 million in 2023Q4, despite the recent reduction in capital expenditures.
| Cash from Operations | -4.88M | -5.26M | -11.41M | -49.48M | -65.07M | -53.67M | -37.32M | -33.58M | -19.24M | -12.95M | -4.13M | -1.57M |
| Operating CF Margin % | - | - | - | - | - | - | - | - | - | - | - | - |
| Operating CF Growth % | 137.5% | 53.86% | 76.94% | 23.96% | -21.24% | -43.81% | -11.13% | -74.5% | -48.63% | -213.59% | -162.83% | - |
| Net Income | -2.72M | -1.92M | -15.75M | -51.6M | -77.53M | -66.37M | -60.02M | -46.39M | -30.66M | -31.29M | -12.65M | -4.47M |
| Depreciation & Amortization | 0 | 41K | 823K | 2.23M | 3.03M | 2.31M | 1.78M | 1.37M | 630K | 2K | 0 | 0 |
| Stock-Based Compensation | 91K | 129K | -450K | 568K | 2.28M | 3.31M | 2.99M | 2.66M | 4.96M | 2.01M | 0 | 0 |
| Deferred Taxes | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Other Non-Cash Items | -1.71M | -1.83M | 4.6M | 2.31M | 3.12M | 7.73M | 14.83M | 8.64M | 3.36M | 15.73M | 7.86M | 2.34M |
| Working Capital Changes | -545K | -1.68M | -628K | -2.98M | 4.03M | -637K | 3.09M | 132K | 2.47M | 597K | 663K | 558K |
| Change in Receivables | 250K | 435K | 494K | -3.58M | 14K | -35K | 4K | -19K | -35K | -106K | 0 | 0 |
| Change in Inventory | 0 | 0 | 0 | 0 | -14K | 35K | -4K | 19K | 0 | 0 | 0 | 0 |
| Change in Payables | 174K | 0 | -2.97M | 192K | 5.3M | -175K | 3.15M | 296K | 2.47M | 1.33M | 668K | 0 |
| Cash from Investing | 0 | 1.17M | 0 | 5.89M | -2.95M | -5.37M | -4.41M | 13.91M | 557K | -29.05M | 0 | -2M |
| Capital Expenditures | 0 | 0 | 0 | -64K | -3.08M | -5.37M | -4.41M | -3.69M | -7.95M | -2.8M | 0 | 0 |
| CapEx % of Revenue | - | - | - | - | - | - | - | - | - | - | - | - |
| Acquisitions | 0 | 0 | 0 | 0 | 127K | 0 | 0 | 0 | 1.07M | -2.38M | 0 | 0 |
| Investments | - | - | - | - | - | - | - | - | - | - | - | - |
| Other Investing | 0 | 1.17M | 0 | 5.95M | 0 | 0 | 0 | 0 | -1.07M | 2.12M | 0 | -2M |
| Cash from Financing | 6.91M | 14.53M | 11.27M | -26.08M | 34.06M | 70.85M | 78.12M | 65.12M | 181K | 49.98M | 31.63M | 3.57M |
| Debt Issued (Net) | 0 | 0 | 0 | -30.38M | 30M | 0 | -15.75M | 15M | 0 | -320K | -3.38M | 0 |
| Equity Issued (Net) | 6.91M | 14.53M | 9.15M | 4.56M | 6.62M | 71.92M | 97.03M | 54.14M | 0 | 50.3M | 35.01M | 0 |
| Dividends Paid | 0 | 0 | -611K | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Share Repurchases | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Other Financing | 0 | 0 | 2.73M | -267K | -2.57M | -1.07M | -3.16M | -4.02M | 181K | 0 | 0 | 3.57M |
| Net Change in Cash | 2.03M | 10.43M | -145K | -69.67M | -33.96M | 11.81M | 36.39M | 45.44M | -18.51M | 7.98M | 27.5M | 0 |
| Free Cash Flow | -4.88M | -5.26M | -11.41M | -49.59M | -68.14M | -59.03M | -41.73M | -37.28M | -27.19M | -15.75M | -4.13M | -1.57M |
| FCF Margin % | - | - | - | - | - | - | - | - | - | - | - | - |
| FCF Growth % | 34.7% | 53.86% | 76.99% | 27.23% | -15.44% | -41.46% | -11.95% | -37.1% | -72.66% | -281.38% | -162.83% | - |
| FCF per Share | -0.73 | -1.07 | -1.86 | -5.76 | -9.88 | -10.08 | -11.90 | -15.51 | -15.13 | -9.35 | -2.36 | -2.36 |
| FCF Conversion (FCF/Net Income) | 1.79x | 2.74x | 0.72x | 0.96x | 0.84x | 0.81x | 0.62x | 0.70x | 0.63x | 0.41x | 0.33x | 0.35x |
| Interest Paid | 0 | 0 | 0 | 1.34M | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Taxes Paid | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Imminent liquidity and dilution
As reported in financial statements, the OCF/NI ratio has fluctuated wildly, reaching a peak of 9.08 in 2025Q1, which suggests that reported net losses significantly understate the actual cash burn required to sustain the company's clinical-stage research and development activities during this period.
The persistent divergence between net income and operating cash flow indicates that non-cash charges and working capital adjustments are masking the true intensity of the company's cash depletion. Investors should monitor this gap as it implies that the accounting loss is a poor proxy for the actual capital required to maintain operations.
Based on Mustang Bio's reported figures, the company has maintained a consistent negative free cash flow trajectory over the last ten quarters, with quarterly outflows peaking at $7.3 million in 2023Q4, reflecting the heavy capital requirements inherent in its current clinical-stage biotechnology business model.
The lack of positive free cash flow is a structural reality for a pre-revenue firm, yet the trend suggests that even with cost-cutting measures, the burn remains substantial. This trajectory indicates that the company is entirely reliant on external financing to bridge the gap between its research ambitions and its lack of commercial revenue.
According to recent SEC filings, working capital changes have been highly erratic, swinging from a $4.0 million inflow in 2024Q2 to a $3.2 million outflow in 2024Q4, which suggests significant instability in the timing of payables and the management of operational liabilities.
These fluctuations may indicate that the company is managing its cash position by aggressively timing payments to vendors, a common but unsustainable practice for firms facing liquidity constraints. Such volatility warrants further investigation into whether these shifts represent genuine operational efficiencies or merely temporary deferrals of necessary cash outflows.
As indicated by the company's financial statements, the divestiture of the Worcester facility has effectively eliminated traditional CapEx, yet the cash flow statement obscures the potential for increased future service obligations and the loss of control over critical manufacturing timelines for lead programs.
While the shift to an asset-light model reduces immediate capital intensity, it may shift costs from the balance sheet to the operating expense line through third-party service agreements. Analysts should monitor whether these outsourced manufacturing costs create a new, less visible floor for the company's ongoing cash burn.
Quick answers to the most common questions about buying MBIO stock.
Mustang Bio, Inc. (MBIO) generated $-5.3M in net cash from operating activities in 2025. This reflects the cash generated directly from core business operations.
Mustang Bio, Inc. (MBIO) reported negative free cash flow of $5.3M in 2025, indicating capital requirements exceeded cash from operations.
Mustang Bio, Inc. (MBIO) spent $0.0M on capital expenditures in 2025. CapEx represents the cash invested in physical assets like property, plant, and equipment to maintain or grow the business.