The charge. "Buy the dip" — three words that have launched a million bad entries. The claim is that a down day is a discount, and buying weakness beats buying at random. We put it to two years of Bitcoin.
The evidence
Start with the base rate: on any given day, Bitcoin closes up 49.8% of the time — a coin flip. Now condition on a dip and see if the odds improve:
| You buy after… | Next-day up | Avg next day | Sample |
|---|---|---|---|
| a single down day | 49.0% | +0.02% | 361 |
| an up day (for contrast) | 50.7% | +0.05% | 357 |
| two straight down days | 48.4% | +0.03% | 184 |
| three straight down days | 57.9% | +0.59% | 95 |
| a down week | 52.2% | — | 337 |
The slogan, as people actually use it — see red, buy — is worthless. Buying after one down day (49.0%) is, if anything, slightly worse than buying at random. Two down days: nothing.
The twist
But look at the bottom of the ladder. After three consecutive down days — real, sustained selling — the next day closed up 57.9% of the time, with a positive average. That's the shape of a genuine capitulation bounce: not "buy any dip," but "buy panic."
Cross-examination
Before you build a strategy on it: that's 95 instances. The margin of error is roughly ±5 points, so 57.9% is suggestive, not proven — it could still be a fluke, and it says nothing about how far the bounce runs or whether it survives fees. It's a lead, not a law.
The verdict
"Buy the dip" as a reflex is a slogan, and the data is blunt about it. But buried underneath is a real hint that deep selloffs mean-revert — and we won't debunk it or endorse it on 95 data points. This one stays open, and we'll keep watching it. Honest beats tidy.