I'm looking to hedge a S&P portfolio with index options that have the best liquidity, tight B/A spread and track close to 1:1 with the index. For what I found so far it looks like the SPX options have the best of both. I would like to trade the ES options for round the clock trading but they look thinly traded and hard to trade out of during extremes. Is this correct ? Are there are any others I've missed ?