If you want to daytrade the s&p, is there any advantage to trading the futures versus trading SPY. Assume i don't care about leverage as i work as prop trader. My maximum trade will be about 10k shares worth of SPY. (a little shy of $1 million). Would i be at a disadvantage trading SPY versus those that trade the futures?? What are advantages if any of futures other than the leverage? Are the fills better? Never traded futures myself.