FindingSAVNG Research · September 10, 2026

Insider buying pays in sell-offs, not in calm markets

The claim. If you had bought the same stock the day after every any opportunistic buy became public, from 2006 to 2026, and held for three months, you would have beaten small caps by +3.7 pts on average when the market was in a sell-off (17,563 trades, very unlikely to be luck) and by +1.4 pts when it was calm (51,850 trades, unlikely to be luck). All states together: +2.0 pts across 69,413 trades.

Copying every opportunistic insider purchase barely beats small caps when the market is calm. The same trades beat the market clearly when it is being sold off.

How we tested it
  • Trades: every open-market insider purchase reported to the SEC on Form 4 from 2006 onward that passes our routine-versus-opportunistic filter; for this piece, every open-market purchase that passes the routine-vs-opportunistic filter.
  • Entry: first session after the filing became public. Held 63 trading days (about three months).
  • Benchmark: IWM (small caps), because insider-buy candidates skew small and cheap; beating the S&P alone would just be that tilt.
  • Market state: stress = SPY at least 10% below its trailing 1-year high on the entry day; calm otherwise.
  • Statistics: clustered by company (one vote per company) — five insiders buying the same stock in the same week count once. Cells under 40 trades or 15 companies are shown but greyed. No trading costs deducted.
  • What is excluded: companies without a ten-year price history (delisted names are the main gap; see the survivorship note on the evidence page).
Reproduce: node savng-insider-history/sector-findings.js → reports/sector-findings.json (generated 2026-09-10); served at /research-data.
The picture
Medical devices+23.0 pts n 340Transport & logistics+16.4 pts n 172Other+10.8 pts n 928Construction+10.2 pts n 113Tech hardware & semis+9.0 pts n 474Retail & consumer+7.6 pts n 694Energy+7.4 pts n 644Biotech & pharma+6.5 pts n 575Software & IT services+5.4 pts n 592Industrials & manufacturing+4.9 pts n 2,366Finance & real estate+4.4 pts n 367REITs+3.8 pts n 1,018Services+2.2 pts n 1,044Insurance+1.4 pts n 663

Three-month excess return versus small caps for any opportunistic buys made during sell-offs, by sector. Sectors with too few trades omitted from the chart, shown in the table.

Does it apply to your sector?
Sector (SEC industry group)In sell-offsIn calm marketsRead
Medical devices +23.0 pts n 340 · t 2.8 +3.6 pts n 1,322 · t 0.7 Sell-offs only
Transport & logistics +16.4 pts n 172 · t 1.8 +4.1 pts n 603 · t 2.0 No reliable edge
Other +10.8 pts n 928 · t 2.7 +1.9 pts n 1,734 · t 0.9 Sell-offs only
Construction +10.2 pts n 113 · t 3.5 −6.0 pts n 429 · t -1.1 Sell-offs only; loses in calm
Tech hardware & semis +9.0 pts n 474 · t 3.2 −2.6 pts n 1,300 · t -2.6 Sell-offs only; loses in calm
Mining & metals +7.6 pts n 118 · t 1.3 −1.7 pts n 466 · t -0.9 Too few trades to say
Retail & consumer +7.6 pts n 694 · t 3.4 +1.7 pts n 2,116 · t 1.9 Sell-offs only
Energy +7.4 pts n 644 · t 2.7 −1.5 pts n 1,713 · t -2.0 Sell-offs only; loses in calm
Biotech & pharma +6.5 pts n 575 · t 1.9 +4.9 pts n 1,809 · t 1.5 No reliable edge
Healthcare services +6.3 pts n 72 · t 1.0 +1.2 pts n 343 · t 2.1 Too few trades to say
Food, drink & tobacco +5.6 pts n 84 · t 0.4 +1.9 pts n 334 · t 0.9 Too few trades to say
Telecom & media +5.6 pts n 70 · t 1.1 −2.5 pts n 504 · t 0.1 Too few trades to say
Software & IT services +5.4 pts n 592 · t 1.6 +0.4 pts n 1,414 · t 0.5 No reliable edge
Industrials & manufacturing +4.9 pts n 2,366 · t 4.2 +2.9 pts n 5,945 · t 2.2 Works in both states
Finance & real estate +4.4 pts n 367 · t 0.8 +0.6 pts n 1,318 · t 0.3 No reliable edge
REITs +3.8 pts n 1,018 · t 0.6 +1.3 pts n 2,445 · t 0.4 No reliable edge
Services +2.2 pts n 1,044 · t 1.9 +2.2 pts n 2,601 · t 1.0 No reliable edge
Insurance +1.4 pts n 663 · t -0.4 +1.2 pts n 1,473 · t 1.2 No reliable edge
Utilities +0.9 pts n 629 · t 0.6 +0.6 pts n 1,893 · t -0.1 No reliable edge
Banks −1.0 pts n 5,034 · t 0.2 +1.5 pts n 16,799 · t 4.9 Calm markets only

t is the clustered t-statistic: above 2 means the result is unlikely to be luck; above 3, very unlikely. "n" is trades.

Where it applies today
Where it does not apply
Banks and utilities show no edge in any state. In calm markets the edge is thin enough that trading costs can remove it.

SAVNG is an educational research publication, not a Registered Investment Adviser. Everything here is general-circulation information produced by an automated pipeline — the same for every reader — and is not personalized investment advice, an offer, or a recommendation to buy or sell any security. Any performance figure is hypothetical; past performance does not predict future results. Details.

Published by SAVNG Research. Every figure on this page is read from the study data at render time; if the study changes, the page changes with it.

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