Short answer: no. Insider purchases of $1 million or more beat the S&P 500 over the next 90 days 44.0% of the time (3,279 cases since 2020). That's slightly worse than insider buys in general (45.8%), and the typical $1M+ buy trailed the index by 2.5 points.
It feels backwards. A director who puts $5 million of their own money in must know something, right? Here's what the filings show.
Results by size of the buy
Every open-market purchase (Form 4 code P) since 2020, grouped by the dollar amount bought, measured from the day the filing became public:
| Size of the buy | Cases | Beat the S&P 500 | Median vs. S&P 500 |
|---|---|---|---|
| Under $250K | 10,219 | 45.8% | −1.5 pts |
| $250K to $1M | 3,401 | 47.4% | −1.2 pts |
| $1M or more | 3,279 | 44.0% | −2.5 pts |
| All insider buys | 16,899 | 45.8% | −1.6 pts |
The middle group did best, but by less than two points, and none of the three groups beat the market more often than not.
Did it hold up after 2023?
A pattern that's real should show up in both halves of the data. We split at April 2023:
| Size of the buy | Before Apr 2023 | Apr 2023 onward |
|---|---|---|
| Under $250K | 46.8% | 44.8% |
| $250K to $1M | 49.8% | 45.4% |
| $1M or more | 45.9% | 42.3% |
The mid-size "edge" mostly came from the early years. From April 2023 onward it shrank to under a point above the overall rate. Big buys were the weakest group in both halves.
When the CEO or CFO writes the big check
| Setup | Cases | Beat the S&P 500 | Median vs. S&P 500 |
|---|---|---|---|
| $250K–$1M, CEO or CFO buying | 1,249 | 49.1% | −0.4 pts |
| $1M+, CEO or CFO buying | 985 | 42.5% | −3.2 pts |
| $1M+, 3 or more insiders | 756 | 44.8% | −2.3 pts |
| $1M+, stock down 20%+ first | 902 | 45.0% | −2.3 pts |
The best line in the whole table is still under 50%. Many of the largest purchases come from 10% owners and investment firms adding to big stakes, which is a different situation from an executive betting a meaningful share of their own wealth. The dollar figure alone doesn't tell you which one you're looking at.
What this means for you
- Size is not a signal by itself. Don't rank insider buys by dollar amount alone.
- Look at the person and the stake. A $300,000 buy that raises a CEO's stake by 40% is a different kind of bet from a $3 million add by a fund that already owns 15%.
- Check the history for the exact setup. Every stock page on InsiderPrint now has a quick backtest set to that stock's latest buy.
Try it yourself
- Change the size and any other trait in the Backtester. It shows the before/after-2023 split for every setup.
- Find recent big buys with the plain-English screener.
- See what happened 7, 30 and 90 days after this year's largest purchases in After the buy, losses included.
Method: open-market purchases by officers, directors and 10% owners of U.S.-listed stocks, Jan 2020 onward, grouped into one event per stock per 14-day window. Returns are price changes from the first close after the filing date, before costs and dividends, compared with the S&P 500 (SPY) over the same days. Penny stocks are excluded. Details in our methodology. History, not advice.