We ran 360 honest backtests and judged the 312 with enough trades — only 9% beat buy & hold

What this number means for your idea

Pick a famous strategy and a famous asset at random and the honest odds are that the combination lags buy & hold — most do. That's your starting prior: a new idea is more likely to underperform holding than to beat it, before you've looked at anything specific. It doesn't mean nothing works — a real minority genuinely beats. It means the burden of proof is on the strategy, and “it looked good in a backtest” is not that proof (a good-looking backtest is often just luck).

These are famous names that still trade today. Companies that delisted or went bankrupt aren't in the set (survivorship bias) — and that history isn't available from the free public data this tool runs on — so this rate isn't a representative base rate for every stock that has ever traded.

Why most of them lag

• • Buy & hold is a strong benchmark. It has zero trading costs, stays fully invested, and collects dividends. A rule that steps in and out has to overcome all of that friction just to draw level.
• • Costs are charged here. Fees and slippage on every fill quietly turn many “profitable” rules negative — the friction was always real; most backtests just hide it.
• • The winners often won for an unflattering reason. A strategy most often beats buy & hold on an asset that fell over the window — sidestepping the decline is where the timing added value. That's a statement about the asset's decline as much as the strategy's skill.