Free cash flow remains deeply negative, with a -49.1% margin in 2026Q1, highlighting a persistent reliance on cash reserves that have dwindled from $83.5 million in 2023Q4 to $61.6 million.
| Cash from Operations | -29.3M | -32.45M | -31.54M | -37.61M | -45.14M | -41.43M | -30.63M | -20.77M | -18.39M |
| Operating CF Margin % | - | -35.85% | -37.64% | -54.77% | -84.11% | -85.57% | -93.58% | -63.71% | -91.95% |
| Operating CF Growth % | 37.13% | -2.88% | 16.15% | 16.67% | -8.95% | -35.24% | -47.52% | -12.89% | - |
| Net Income | -53.21M | -54M | -56.39M | -60.84M | -58.92M | -48.66M | -32.23M | -20.7M | -18.48M |
| Depreciation & Amortization | 1.2M | 1.15M | 1.49M | 1.55M | 4M | 3.16M | 483K | 365K | 270K |
| Stock-Based Compensation | 5.17M | 0 | 22.95M | 22.1M | 0 | 0 | 3.2M | 364K | 366K |
| Deferred Taxes | 0 | 0 | 0 | 0 | 49K | -6K | 0 | 746K | 936K |
| Other Non-Cash Items | 16.27M | 22.33M | 2.11M | 2.14M | 16.8M | 11.92M | 2.71M | 864K | 36K |
| Working Capital Changes | 1.28M | -1.93M | -1.7M | -2.56M | -7.06M | -7.84M | -4.79M | -2.4M | -1.52M |
| Change in Receivables | 3M | 1.07M | -1.31M | -3.1M | -2.19M | -2.43M | 1.46M | -2.52M | -262K |
| Change in Inventory | -2.13M | -765K | -229K | 918K | -3.64M | -6.46M | -5.05M | -2.61M | -1.25M |
| Change in Payables | -665K | 270K | 2.28M | -345K | 247K | 87K | 592K | 524K | -648K |
| Cash from Investing | 14.16M | 30.48M | 17.48M | -2.01M | -4.22M | -46.26M | 12.69M | -14.23M | 200K |
| Capital Expenditures | -160K | -452K | -1.45M | -807K | -1.32M | -3.67M | -911K | -720K | -316K |
| CapEx % of Revenue | 0.18% | 0.5% | 1.73% | 1.18% | 2.46% | 7.58% | 2.78% | 2.21% | 1.58% |
| Acquisitions | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 13.51M | 16K |
| Investments | - | - | - | - | - | - | - | - | - |
| Other Investing | 0 | 0 | 0 | 0 | 0 | 0 | 0 | -13.51M | 16K |
| Cash from Financing | 2.24M | 903K | 1.36M | 21.4M | 2.47M | 4.5M | 234.83M | 45.62M | 12.11M |
| Debt Issued (Net) | 1.69M | -100K | -95K | 19.91M | -87K | 0 | 32.99M | 6M | 12M |
| Equity Issued (Net) | 375K | 1M | 0 | 0 | 2.56M | 4.5M | 201.39M | 39.67M | 0 |
| Dividends Paid | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Share Repurchases | 0 | 0 | 0 | 0 | -27K | -26K | 0 | -12K | 0 |
| Other Financing | 182K | 0 | 1.46M | 1.49M | 0 | 0 | 446K | -52K | 114K |
| Net Change in Cash | -12.98M | -1.15M | -12.62M | -18.18M | -46.74M | -83.08M | 217.03M | 10.64M | -5.93M |
| Free Cash Flow | -29.46M | -32.9M | -32.98M | -38.42M | -46.45M | -45.1M | -31.54M | -21.48M | -18.71M |
| FCF Margin % | -33.27% | -36.35% | -39.37% | -55.94% | -86.57% | -93.15% | -96.37% | -65.92% | -93.53% |
| FCF Growth % | 14.02% | 0.26% | 14.14% | 17.3% | -3% | -42.97% | -46.82% | -14.83% | - |
| FCF per Share | -0.70 | -0.81 | -0.84 | -1.01 | -1.25 | -1.25 | -0.88 | -0.61 | -0.90 |
| FCF Conversion (FCF/Net Income) | 0.55x | 0.60x | 0.56x | 0.62x | 0.77x | 0.85x | 0.95x | 1.00x | 1.00x |
| Interest Paid | 792K | 0 | 3.48M | 2.98M | 0 | 0 | 3.06M | 1.4M | 1.36M |
| Taxes Paid | 150K | 0 | 556K | 471K | 0 | 0 | 259K | 196K | 226K |
Persistent operating cash burn
According to the provided financial data, Pulmonx consistently reports net losses that exceed operating cash outflows, with the OCF/NI ratio fluctuating between 0.26 and 0.92 over the last ten quarters, suggesting that non-cash charges and working capital movements are significantly masking the true underlying cash burn.
The persistent gap between net income and operating cash flow indicates that the company's accounting losses are not fully reflective of the actual cash depletion occurring within the business. Investors should monitor this divergence, as it suggests that the company's ability to fund operations is increasingly reliant on external financing rather than internal cash generation.
As reported in recent financial statements, Pulmonx's free cash flow margins remain deeply negative, reaching a low of -65.0% in 2024Q1 and failing to show a sustained path toward break-even, which highlights the structural difficulty in scaling the business model without significant additional capital injections.
The lack of positive free cash flow trajectory suggests that the company's current commercial strategy is not yet yielding the operating leverage required to cover its high fixed-cost base. This trend warrants further investigation into whether the current sales force expansion is actually driving incremental value or merely sustaining existing procedural volumes.
Based on the reported figures, Pulmonx exhibits significant volatility in working capital changes, with quarterly fluctuations ranging from a $4.7 million inflow in 2025Q2 to a $4.8 million outflow in 2025Q1, indicating that cash flow is highly sensitive to the timing of inventory and receivables management.
This erratic working capital behavior suggests that the company may be struggling to optimize its supply chain or collection cycles as it attempts to scale. Such instability in cash conversion cycles may indicate underlying inefficiencies in how the company manages its inventory of Zephyr valves and associated diagnostic sensors.
Analysis of the cash flow statements reveals that stock-based compensation, which reached as high as $5.9 million in 2024Q2, serves as a significant non-cash add-back that obscures the true economic cost of talent acquisition and retention required to maintain the company's current growth trajectory.
By relying on equity-based compensation to manage operating expenses, the company effectively shifts the burden of its cash burn onto shareholders through dilution. This practice warrants further investigation, as it may be artificially inflating the reported operating cash flow figures while failing to address the core issue of negative profitability.
Quick answers to the most common questions about buying LUNG stock.
Pulmonx Corporation (LUNG) generated $-32.4M in net cash from operating activities in 2025. This reflects the cash generated directly from core business operations.
Pulmonx Corporation (LUNG) reported negative free cash flow of $32.9M in 2025, indicating capital requirements exceeded cash from operations.
Pulmonx Corporation (LUNG) spent $0.5M on capital expenditures in 2025. CapEx represents the cash invested in physical assets like property, plant, and equipment to maintain or grow the business.