In a phrase, getting into a trade early. It's what I've devoted heaven knows how many hours figuring out NL derivatives for, and I'm still refining.It applies to everything. Crowded trades product excess variance. Variance lowers your risk adjusted return by definition (it's in the denominator). You are looking for "signal extraction" with the least amount of variance in your trade. That's where alpha comes from. Everything else is just adding leverage to index.
As James Goldsmith said, "If you see a bandwagon, it's too late".