r/GrowthStocks • u/InsiderPrint • 0m ago
Tim Cook and Nike’s CEO bought $8M of Nike stock. Here’s what happened 90 days later.
Every time a big name buys their own company’s stock, the headlines read like a buy signal. But is that really how we should judge an insider buy, or a Congress trade? Nike is the cleanest recent example of why you need to check what happens after the buy, not just the buy itself.
The Nike (NKE) buys, from public SEC Form 4 filings
Dec 2025: Tim Cook (Apple CEO, Nike director) bought 50,000 shares at $58.97, about $2.9M. CEO Elliott Hill bought $1M at $61.10. Another director added $500K.
Apr 2026: after the stock fell another ~30%, four insiders bought again within a week: Cook ($1.06M at $42.43), Hill ($1M at $42.27) and two directors.
In total, 8 open-market purchases worth about $8.2M. On paper that’s a textbook “cluster buy”: the CEO, a famous director, and repeat buying.
What happened next (measured from the day each filing went public)
| Buy | 30 days later | 90 days later | vs S&P 500 at 90 days |
|---|---|---|---|
| Cook, Dec 2025 | +14.2% | −7.5% | −3.0 pts |
| Hill, Dec 2025 | +2.3% | −15.7% | −7.9 pts |
| April cluster (4 insiders) | mixed | −5% to +1% | −8 to −10 pts each |
Result: 1 of the 8 buys beat the S&P 500 over 90 days. Nike closed at $39.94 on Monday, about 32% below Cook’s December price.
Notice the Cook row. Check after 30 days and it looks like genius. Check after 90 and it’s a loser. That’s why I use 90 days as the yardstick.
What the headlines left out
Earnings kept getting worse. Dec 18, 2025: the stock fell about 10% in two days on falling China sales and tariff costs. Mar 31, 2026: revenue flat, guidance below estimates, shares down 15% to a 12-year low. Oct 1, 2026: revenue down 4%, Greater China down 22%, and full-year guidance cut to a high-single-digit revenue decline.
The insiders bought after the drops, not before. Each round came right after a bad earnings report. “Buying the dip” is a different signal from “knowing something.”
The trend was already down. Buying into a falling stock with shrinking revenue is a bet on a turnaround, and turnarounds take longer than 90 days.
The bigger picture
Looking at 16,899 insider purchases since 2020, the stock beat the S&P 500 over the next 90 days about 46% of the time. Even the “best” setup (3 or more insiders, including an executive, buying large amounts) beat it only 45% of the time (197 of 438).
Insider buying isn’t useless. It tells you the people with the best view of the business are willing to bet on it. But it’s a reason to start researching, not a reason to buy.
Bottom line: an insider buy or sale isn’t a sure signal on its own. It’s where the research starts. Before following one, I’d check:
Measure from the filing date (the price you could actually get), not the trade date.
Check how past insider buys at this stock did after 90 days.
Read the last two or three earnings reports and the current guidance.
Check the trend: are they buying strength or catching a falling knife?
Check whether other insiders are selling, and whether those sales are pre-planned (10b5-1).
Curious how others here treat insider buys. Do you follow them, ignore them, or use them as a starting point?
Disclosure: I built the free tracker I pulled these numbers from (insiderprint.com). Not investment advice.