On another note,there is no inherent mathematical edge to selling an option vs buying it.
That belief should get filed with "90 percent of options expire worthless"...
I did run a very simple backtest on buying the 30day SPY ATM call vs selling the 30 day ATM put,rolling both..
Over the last 10 years,selling the put returned apx 2x with significantly better risk measures.
Both strategies underperformed buying the SPY,with the short ATM put returning slightly over half of the long SPY return
For the record,it was a very simple backtest..
that’s what you would expect.
Selling options has an edge but only a small one. The equilibrium is sellers trying to capture this edge and the buyers willing to pay it to protect greater returns from delta.