I spent years looking for the one system. The fixed set of rules that would just print. I want to save you that time.

Here's the thing I got wrong: I thought of an edge like a machine. Build it once, flip it on, collect. So every time a strategy stopped working, I assumed I broke it — bad discipline, a missed signal, emotions. I'd go rebuild the same dead machine.

The machine didn't break. The market changed around it.

An edge is just a price discrepancy — a spot where the market pays more than the risk is worth. But a discrepancy is something other people can see too. You trade it, a fund copies it, orders push price to fair value, and the move disappears. Academics even named it: post-publication decay. After anomalies get published, their returns tend to drop by a third to a half. Discovery is the start of decay, not the start of profit.

So the core insight is simple and a little humbling: you don't own an edge, you rent it — and the rent goes up as more people move in.

What a disciplined trader does about it: stop hunting the perfect system. Learn to tell decay from variance. Variance is random losses scattered around your win rate. Decay is structural — losses cluster, winners shrink, fills get worse. Log expected value in rolling windows. When the trend bends down and stays down, that's not bad luck. That's the rent going up, and it's time to retire that edge.

And invest in the three things that don't decay: risk discipline (size so no single loss can hurt you), adaptability (treat strategies as disposable, process as permanent), and structural advantage (low costs, execution, temperament — things the crowd can't copy from you).

Quick reminder: this is educational commentary, not personalized financial advice. I share trades as examples of a process.

Full breakdown with the 2021 zero-day options example is here: https://youtu.be/G9gKje8zouc

Trade the process. Let the edges come and go.