Yet, they are not the same. Every country has different income tax levels for equities vs futures. Future in the US are much better. Also, even though SPY trades pre and post market, the hours are limited to 4am to 8pm if you have that access and early morning and evening liquidity is limited. ES trades 22 hours and 15 min per day,
So I suppose being that different it would probably ruin using an SPY strategy to the /ES???
