Test #4 · Video comes out Sunday, Oct 25 · 12:00 PM ET
Miss the 10 best days in the stock market and lose half your money? We tested 30 years of real data
The video comes out Sunday, Oct 25 · 12:00 PM ET.Subscribe on YouTube to see it the minute it's up, or get the free weekly email for the full numbers.
The claim
Time in the market beats timing the market. Fund companies show a chart every year: one tall bar for the person who stayed invested, then shorter bars for people who missed the market's best days. Hartford Funds, a mutual fund company, says that if you missed the market's 10 best days over the past 30 years, "your returns would have been cut in half." Its chart, the S&P 500 from 1996 to 2025, shows $10,000 growing to $192,167 fully invested and $85,490 after missing the 10 best days (56% less). J.P. Morgan shows its own version in its Guide to Retirement 2026.
Source: Hartford Funds, "Timing the Market Is Impossible" (fetched October 9, 2026)
How we are testing it
- $10,000 put into the S&P 500 at the close on January 2, 1996, with every dividend reinvested as the SPY index fund paid them, and held to October 8, 2026: 7,742 trading days, 30.77 years.
- The same money again, skipping the 10, 20 and 30 best days. On a skipped day the money sits in Treasury bills (T-bills, short-term U.S. government debt) and earns one day of interest.
- Then the reverse: skipping the 10, 20 and 30 worst days, and skipping the best and worst days together.
- A panic seller: sells at the close of any day the S&P 500 falls 5% or more, sits in T-bills, and buys back once 3 calm months pass with no new 5% drop. This main version was fixed before looking at results. We also ran 15 versions in all: 3%, 4% or 5% drops, back after 1, 3 or 6 calm months, a calm year, or a new high.
- We also ran Hartford's own years, 1996 to 2025, to check our numbers against its chart.
- No taxes or trading costs, which would only hurt the people jumping in and out. Not adjusted for inflation.
The verdict
The verdict and every number come out with the video, Sunday, Oct 25 · 12:00 PM ET. The free weekly email has the full numbers.
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Education and entertainment only. Not personal financial advice. Your situation is different; talk to a professional before selling or moving your investments. Disclosure: I don't own an S&P 500 index fund. I do own some individual stocks, including Apple, which is part of the S&P 500. Nobody paid for this video.