Insider Buying and Selling Explained
When executives buy or sell their own company's stock.
Published by Wall Street Score. Editorial standards.
Published 2026-08-02 · Updated 2026-10-09
Simple answer
Insider buying and selling tracks when a company's executives, directors, or major shareholders buy or sell shares of their own stock.
Why this matters
Disclosed insider transactions help you investigate changes in ownership, but the filing does not reveal the insider's full motives or future returns.
Good signs
Cluster buying by multiple insiders, especially with personal funds, can be a positive signal.
Warning signs
Selling may reflect liquidity, taxes, diversification or a trading plan. It is not proof that management expects the business to deteriorate.
Easy mistake to make
Treating every insider sale as a red flag — executives sell for many personal reasons unrelated to company health.
How Wall Street Score helps
WallStreetScore shows insider activity on supported stock pages and factors it into the ownership assessment.
Identify the transaction type
Form 4 distinguishes purchases and sales from awards, derivative exercises, tax-related dispositions and gifts. Codes P and S can cover transactions on an exchange or with another person; they should not automatically be described as exchange trades. Check the code and footnotes before interpreting a change as an insider putting new cash at risk.
The acquired/disposed indicator is different from the transaction code. An acquisition can be compensation rather than a purchase. Options and common shares also have different exposures.
Calculate changes against the right ownership base
Hypothetical example: an insider with 200,000 shares sells 10,000 and retains 190,000. The sale is 5% of the original stake, not 5% of the company. If the company has 100 million shares outstanding, those 10,000 shares are 0.01% of the company. Direct and indirect holdings, multiple transactions and corporate actions can complicate this calculation.
Do not infer personal wealth from a filing. Compare disclosed holdings on a consistent basis and avoid adding amended filings as new trades.
Keep observations separate from motive
A purchase can be a research lead, but it does not prove that favorable news is coming or that the price will rise. Sales can serve liquidity or diversification needs. Check the transaction date, reporting delay, footnotes and any disclosed trading-plan context.
Read the company's financials and valuation independently. The WSS insider score summarizes available records; it is neither a dollar total nor a measure of the insider's private information.
Further reading and verification
References explain the underlying concepts; they do not endorse Wall Street Score's model.
Apply this to a real stock
Use Wall Street Score to search a company and compare its score with revenue, earnings, cash, debt, valuation and risks.
Educational research only. Not investment advice.