People often confuse positive expectancy with “easy money.”
They are not the same thing.
Imagine a game where:
* 50% chance to gain +80%
* 50% chance to lose -50%
* You are forced to go all-in every round
At first glance, this looks amazing.
The expected return per trade is positive:
`0.5*80%+0.5*(-50%)=+15%`
Most people stop thinking here and conclude:
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But reality is more complicated because markets are **non-ergodic**.
If you lose 50%, you now need a 100% gain just to recover.
The distribution becomes highly skewed:
* Most traders slowly decay or blow up
* A tiny minority hit long winning streaks and become extremely wealthy
* The mean outcome can be positive
* But the mode (most common outcome) is negative
This is why heavy position sizing destroys traders.
Not because their strategy is necessarily bad.
But because volatility + compounding + time create a mathematical trap.
Professional traders survive by controlling:
* position sizing
* leverage
* tail risk
* drawdown depth
The goal is not maximizing expected return.
The goal is surviving long enough for the edge to compound.
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