But that can't possibly be the case -- since such a simple strategy is already priced into the red.

Anything accessible to any person without days/weeks of research or insider knowledge is already priced-in. All the people rationally "buying the dip" are doing so as the price dips.

Any time you buy, you are betting on a future price against everyone else making bets. Most of those other people, who can move markets, are spending their entire lives in R&D to eek out a slightly better bet.

You're a mark if you think you can price better than them -- and they are the ones presently setting the price.