Mirum Pharmaceuticals, Inc. (MIRM) Cash Flow Statement

The massive divergence in 2026Q2 is driven by a $62.0M working capital source and $66.8M in SBC, but the $273.0M operating cash outflow far exceeds the net loss, indicating that cash consumption is significantly higher than accounting losses suggest. In contrast, 2025Q3 showed a positive OCF of $39.7M against a small net profit, highlighting quarter-to-quarter volatility. Investors should monitor whether the 2026Q1 net loss of -$790.2M, likely a non-cash impairment, is a one-time event or signals recurring cash burn.

The trajectory shows a clear inflection point: after three quarters of positive or near-breakeven FCF in 2025, 2026Q1 and Q2 saw massive outflows, with cumulative FCF over the last two quarters at -$503.1M. This suggests that the company's commercial ramp is consuming cash faster than revenue growth can offset, possibly due to inventory builds or one-time payments. The positive FCF in 2025Q3 appears anomalous relative to the broader trend, warranting scrutiny of what drove that quarter's working capital release.

The working capital line is a major source of volatility: in 2026Q1, a $102.2M positive adjustment partially offset the operating loss, but in 2026Q2, a $62.0M source was insufficient to prevent a $273.0M outflow. This suggests that the company may be stretching payables or collecting receivables aggressively, but the inconsistency across quarters indicates a lack of stable cash conversion. Investors should assess whether these swings reflect genuine operational efficiency or timing distortions, as they materially affect reported OCF.

Capex is negligible relative to revenue, which is typical for a biotech that outsources manufacturing and relies on partnerships. The low capital intensity means that free cash flow is almost entirely driven by operating cash flow, making working capital and expense management the key levers. This also implies that the company does not require heavy fixed-asset investment to grow, but the lack of capex may limit internal manufacturing flexibility.

The absence of shareholder returns is consistent with a growth-stage biotech that is still burning cash. However, the scale of operating cash outflows in 2026Q2 (-$273.0M) suggests that the company may need to raise external capital or draw down existing reserves to fund ongoing operations. Investors should monitor the company's cash position and financing activities, as the current burn rate is not sustainable without additional funding.