Most clinical-stage biotechs generate no revenue. They burn $5–50M per quarter funding clinical trials, payroll, and manufacturing scale-up. The company's survival depends on a single number: cash runway — how long the current cash position lasts at the current burn rate.
For traders, cash runway is the most important number on a biotech balance sheet. A drug-development thesis is irrelevant if the company runs out of money before the readout.
How to calculate it
The calculation is simple:
```
Cash runway (months) = Cash + Short-term investments
÷ Quarterly cash burn × 3
```
The numerator: from the latest 10-Q balance sheet, Cash and cash equivalents + Short-term investments.
The denominator: cash used in operating activities (from the cash flow statement) over the most recent quarter, annualized into a monthly burn rate. Some companies also include capex.
Most biotechs disclose runway directly in the management discussion section of the 10-Q ("we expect our current cash position to fund operations through Q2 2027").
Why "into Q[X] of [year]" matters
Companies disclose runway with calendar precision because investors price the gap between cash exhaustion and the next material catalyst:
- Runway extends past the next catalyst → company can wait for data, then raise from strength
- Runway expires before the catalyst → company must raise before the catalyst, usually at a discount (dilution risk)
- Runway just barely covers the catalyst → most dangerous; if data is mixed, the company has no leverage
A common pattern: the catalyst hits, the stock pops, the company does a follow-on offering within 48 hours.
What dilution looks like
Biotech follow-on offerings typically come at a 5–15% discount to the prior-day close, with additional warrants for the underwriters. A company with 50M shares outstanding doing a $100M raise at $5/share adds 20M shares — a 40% dilution event.
Common dilution vehicles:
- Follow-on equity offering — the standard; priced at a discount
- ATM (At-the-Market) program — drip-sells shares into the market over months; less visible, often used between catalysts
- PIPE (Private Investment in Public Equity) — direct sale to institutions; often includes warrants
- Convertible notes — debt that converts to equity above a threshold
Runway events to watch
- Initial S-3 shelf registration — sets up the option to raise; not the raise itself
- ATM program disclosure — signals dilution is happening continuously
- 8-K filing about a follow-on offering — immediate dilution event
- PIPE announcements — usually 8-K Item 1.01
Practical traders' heuristics
- A company with <12 months of runway is in the danger zone
- A company with <6 months of runway will dilute soon — often within weeks
- A company with >24 months of runway has flexibility; can wait for the best catalyst window
Yeji coverage
Cash position and quarterly burn are pulled from 10-Qs as they're filed. We surface runway estimates on the ticker page and flag dilution risk catalysts when runway drops below 12 months. Material 8-Ks (financings, ATM disclosures) appear in the catalyst feed automatically.