'Just add a trailing stop': less profit in all 3 families

Source: Common trading advice

Win rate goes up, profit goes down.

The one try that looked better is what luck looks like.

This verdict is about the strategy as published, not about the person who shared it.

The claim

Here’s what the strategy promises, in its own terms.

A trailing stop locks in gains and improves almost any strategy.

How we tested it

Same six checks as everything else here: random entries, coin flips, a look-ahead audit, unseen years, double costs and a luck check. How we test →

What we found

Six trailing-stop variants added to 19 of our own strategies (3 families), each test first proven to reproduce the strategy's own backtest exactly. Every family got worse: one group went from +203R to between +62R and +169R, another from +143R to +67R to +114R. Win rates went up, profit went down, because the trail cuts the winners that pay for the losers. One of about 60 tries looked better in both windows, which is what luck looks like.

The numbers

The headline numbers from our test.

Strategies	19
Trail variants	6
Family1	203 -> 62..169
Family2	143 -> 67..114
Variants better in both windows	1 of ~60

• Profit factor: money won divided by money lost. Below 1.0 loses money. Around 1.0 is break-even.
• R-multiple: profit or loss measured in units of the amount risked per trade. +1R means you made what you risked.
• vs random: how the strategy did against the same trades with random entries.