Grid is bad, but are mean-reversion bands worse? A failed-ideas thread

[FXS London Scalper]

Grid strategies have a bad reputation, and for good reason. But some "safer" alternatives fail too, just more quietly. Mean-reversion band strategies (buying at lower Bollinger Band, selling at upper) are an example.

Why band strategies fail:
- They work in ranges, but trends break them repeatedly.
- Stop placement is awkward: too tight and you're stopped by noise, too wide and losses are large.
- On M1, bands react quickly, generating many signals with little edge.
- Costs eat small profits.

This thread is for sharing failed ideas honestly. Not to mock anyone, but to save others time.

Template:
- Idea: what was the logic?
- Test: what data, period, costs?
- Result: what happened?
- Why it failed: your best explanation.

Failed ideas are underreported. Everyone posts winners. A thread of losers might be more educational.

What's your most instructive failed idea?