Why We Don't Stack Similar Trades on Top of Each Other
Two trades can look completely independent and still fail for the exact same reason at the exact same time β if they're both short premium on the same underlying in the same direction, a single sharp move can hit both at once.
This is correlation risk, and it's easy to miss because it doesn't show up trade by trade. It only shows up on the one day everything moves together, which is usually the worst possible day for it to be a surprise.
Spreading trades across different expirations, different strategies, and different account roles isn't just for variety β it's specifically so one bad move in SPX can't hit every position in the exact same way at the exact same time.
A portfolio of trades that all win and lose together isn't really a portfolio. It's one trade wearing several disguises.
Real diversification means asking what actually moves these positions, not just how many of them there are.
