How to Read Biotech SEC Filings: 10-K, 10-Q, 8-K, and S-1

You just bought a biotech after an FDA approval, and the press release looked great. Here is the problem: the press release is a marketing document. The legal documents, the SEC filings, are where the real numbers, risks, and red flags live. If you only read press releases, you are reading the spin.

The solution is to learn the four filings that matter for biotech and read them in the right order. The 8-K is your FDA catalyst feed, the 10-Q is your quarterly cash check, the 10-K is your annual risk audit, and the S-1 is your IPO red-flag screen.

Step 1: Know the four filings and when they drop

• 8-K (current report): filed within 4 business days of a material event. For biotech this is the FDA catalyst filing. Approvals, CRLs (Complete Response Letters), clinical holds, licensing deals, and earnings all land here.
• 10-Q (quarterly report): filed 40 to 45 days after the quarter ends. This is where you find the cash balance, R&D spend, and share count.
• 10-K (annual report): filed 60 to 90 days after the fiscal year ends, depending on company size. Full audited financials plus the Risk Factors section.
• S-1 (IPO prospectus): everything a company must disclose before it sells shares to the public.

Find them all on SEC EDGAR. Search by ticker, filter by form type, and read the actual filing, not a summary.

Step 2: Read the 8-K for FDA catalysts

The 8-K is where biotech is different from every other sector. When the FDA approves a drug, rejects it, or places a clinical hold, the company files an 8-K within 4 business days. Item 8.01, “Other Events,” is the catch-all where approval and CRL press releases go. Item 2.02 is the earnings release.

Real example: Moderna disclosed its norovirus Phase 3 interim-analysis miss in its Q2 earnings 8-K on July 31, 2026, not in a standalone top-line press release. Investors who only watch for press releases missed the signal on the day it filed. If a biotech decision matters to you, set a watch on the 8-K feed for that ticker.

Step 3: Pull the three numbers from the 10-Q

The 10-Q has the numbers the press release omits. Grab three:

• Cash and equivalents (plus short-term investments): this is the runway. Divide it by the quarterly operating burn to get months of runway. Under 12 months means dilution is coming, usually within 90 days. Under 6 months is a countdown. See the dilution survival guide for the full math.
• R&D expense trend: is the pipeline ramping or being cut? Rising R&D funding late-stage trials is healthy. A pre-revenue biotech cutting R&D is usually slowing trials to extend runway, which is a red flag in disguise.
• Shares outstanding: check the cover page against the prior quarter. Up more than 5% means the company is using an ATM (at-the-market) facility to quietly dilute you between reports. For the five numbers that actually move biotech stocks each quarter, see the biotech earnings guide.

Step 4: Read the 10-K Risk Factors with a highlighter

The 10-K Risk Factors section is where the company discloses, in its own words, what could kill it. For biotech, look for three kinds:

• Trial risk: “our Phase 3 trial may fail to meet its primary endpoint.”
• Patent and financing risk: “our patents expire in 202X” and “we may be unable to raise additional capital.”
• Going-concern language: the phrase “substantial doubt about our ability to continue as a going concern” in the auditor’s report or the filing is the loudest red flag in any 10-K.

Approval does not equal survival. Achaogen got its antibiotic plazomicin FDA-approved in June 2018 and filed for Chapter 11 bankruptcy about nine months later. The going-concern note is usually one paragraph, and that one paragraph is the difference between a stock that can survive and one headed to bankruptcy court. For the full red-flag list, see the accounting red flags guide.

Step 5: Screen the S-1 before an IPO

Before you buy a biotech IPO, read the S-1. Four red flags to check:

• Lockup overhang: the standard lockup is 180 days. When it expires, insiders can sell, and the bottom quartile of IPOs drop 10 to 15% relative to the prior month at lockup expiration.
• Insider selling at the IPO: in the “Principal and Selling Stockholders” section, check whether insiders are selling shares into the offering (cashing out) or the company is raising the capital to fund the pipeline.
• Related-party deals: the company licensing its technology from a CEO-controlled entity is a conflict-of-interest red flag.
• “Emerging growth company” (EGC) status: most biotech IPOs are EGCs under the JOBS Act, which lets them disclose less (two years of audited financials instead of three, no auditor attestation on internal controls). EGC is normal, but it means the S-1 is thinner than a mature company’s. For the full IPO evaluation, see the biotech IPO guide.

Common mistakes

• Reading the press release and skipping the filing. The filing has the numbers. The press release has the spin.
• Not watching the 8-K feed. FDA decisions land in 8-Ks within 4 business days, and you want to know the day it files, not when a news site picks it up.
• Missing the going-concern note. It is often one paragraph in the auditor’s report, and it is the difference between a stock that can survive and one headed to Chapter 11.
• Ignoring share-count growth. Stealth dilution via an ATM does not show up as a line item. It shows up as a growing share count.
• Buying an IPO without reading the S-1. The lockup overhang and insider selling are disclosed in plain text. Not reading them is a choice.

Final checklist

• 8-K feed watched for FDA decisions and material events
• 10-Q cash runway calculated; over 18 months preferred
• R&D trend checked: ramping or being cut?
• Share count compared to the prior quarter
• 10-K Risk Factors read, going-concern language checked
• S-1 lockup, insider selling, and related-party sections read before any IPO buy

For the full investing framework, start with how to invest in biotech stocks. For how dilution actually hits shareholders, see the dilution survival guide.