Free cash flow burn has deteriorated to $20.6 million in 2026Q1, with stock-based compensation of $5.5 million providing only a limited buffer against persistent operational cash outflows.
| Cash from Operations | -77.48M | -79.95M | -54.68M | -31.98M | -23.12M |
| Operating CF Margin % | - | - | - | - | - |
| Operating CF Growth % | -81.47% | -46.21% | -71% | -38.3% | - |
| Net Income | -86.61M | -86.97M | -61.92M | -32.56M | -26.14M |
| Depreciation & Amortization | -643K | -3.61M | 244K | 157K | 56K |
| Stock-Based Compensation | 12.32M | 8.68M | 5.22M | 2.04M | 306K |
| Deferred Taxes | 0 | 0 | 0 | 0 | 0 |
| Other Non-Cash Items | -1.83M | 381K | -2.82M | -880K | 1.36M |
| Working Capital Changes | -719K | 1.57M | 4.6M | -735K | 1.29M |
| Change in Receivables | 0 | 0 | 0 | 0 | 0 |
| Change in Inventory | 0 | 0 | 0 | 0 | 0 |
| Change in Payables | 3.08M | -2.46M | 3.93M | 412K | 671K |
| Cash from Investing | -184.03M | -83.7M | -160.59M | -30.93M | -11.41M |
| Capital Expenditures | -2.34M | -1.93M | -874K | -129K | -441K |
| CapEx % of Revenue | - | - | - | - | - |
| Acquisitions | 0 | 0 | 0 | 0 | 0 |
| Investments | - | - | - | - | - |
| Other Investing | 1M | 8.5M | 0 | 0 | 0 |
| Cash from Financing | 277.02M | 189.59M | 234.1M | 69.22M | 46.06M |
| Debt Issued (Net) | 0 | 0 | 0 | 0 | 10M |
| Equity Issued (Net) | 277.02M | 189.59M | 238.04M | 68.51M | 36.49M |
| Dividends Paid | 0 | 0 | 0 | 0 | 0 |
| Share Repurchases | 0 | 0 | 0 | 0 | 0 |
| Other Financing | 0 | 0 | -3.94M | 709K | -428K |
| Net Change in Cash | 15.52M | 25.94M | 18.83M | 6.31M | 11.53M |
| Free Cash Flow | -79.81M | -81.88M | -55.55M | -32.11M | -23.56M |
| FCF Margin % | - | - | - | - | - |
| FCF Growth % | -18.63% | -47.38% | -73.03% | -36.26% | - |
| FCF per Share | -1.71 | -2.24 | -1.66 | -1.01 | -0.74 |
| FCF Conversion (FCF/Net Income) | 0.92x | 0.92x | 0.88x | 0.98x | 0.88x |
| Interest Paid | 0 | 0 | 0 | 0 | 0 |
| Taxes Paid | 0 | 0 | 0 | 0 | 0 |
Clinical trial execution dependency
As reported in quarterly financial statements, MBX consistently records operating cash outflows that closely track net losses, with the OCF/NI ratio fluctuating between 0.81 and 1.26, indicating that non-cash adjustments like stock-based compensation provide only a modest buffer against the company's underlying cash-burning operational structure.
The tight correlation between net income and operating cash flow suggests that the company's losses are primarily driven by cash-intensive R&D activities rather than non-cash accounting charges. Investors should interpret this as a sign that the firm lacks any meaningful operational leverage, as every dollar of loss translates almost directly into a reduction of the company's cash reserves.
Based on the provided cash flow data, MBX's free cash flow trajectory has deteriorated from a quarterly burn of $11.2 million in 2023Q4 to $20.6 million in 2026Q1, reflecting the intensifying capital requirements necessary to support the company's expanding clinical pipeline and ongoing Phase 2 trial activities.
The consistent widening of the negative free cash flow margin suggests that the company is entering a more capital-intensive phase of its lifecycle. This trend warrants close monitoring, as the lack of revenue generation means that the firm remains entirely dependent on external financing to sustain its current research trajectory.
According to recent SEC filings, MBX exhibits significant volatility in working capital changes, ranging from a $2.8 million inflow in 2024Q3 to a $2.9 million outflow in 2023Q4, which appears to be driven by the timing of clinical trial vendor payments and other research-related accruals.
This variability suggests that the company's cash position is sensitive to the timing of its clinical development milestones and vendor management. Analysts should view these fluctuations as a reflection of the company's pre-revenue status, where working capital management is secondary to the immediate necessity of funding clinical trial execution.
As indicated by the financial data, stock-based compensation has grown to $5.5 million in 2026Q1, effectively obscuring the true magnitude of the company's cash-based operating expenses by artificially inflating the net income figure without providing any corresponding benefit to the firm's liquidity or cash runway.
While stock-based compensation is a standard tool for talent retention in biotechnology, its increasing scale relative to the net loss suggests that the company's reported GAAP figures may understate the actual cash cost of its human capital. Investors should focus on the cash-based burn rate to better understand the true financial pressure facing the organization.
Quick answers to the most common questions about buying MBX stock.
MBX Biosciences, Inc. Common Stock (MBX) generated $-79.9M in net cash from operating activities in 2025. This reflects the cash generated directly from core business operations.
MBX Biosciences, Inc. Common Stock (MBX) reported negative free cash flow of $81.9M in 2025, indicating capital requirements exceeded cash from operations.
MBX Biosciences, Inc. Common Stock (MBX) spent $1.9M on capital expenditures in 2025. CapEx represents the cash invested in physical assets like property, plant, and equipment to maintain or grow the business.