QuoteOriginally posted by: winstontjQuoteOriginally posted by: outrunWhen I was a floortrader, the index future trading was triggering index basket trading by us, so futures were leading. The reason was that (stock) basket trading was very expensive from a bid-ask point of view so people trading the index would rather trade the futures. The future was much tighter quoted than the stock because there was supply and demand randomly netting out positions, and so didn't also need to do the expensive basket hedge.I don't know is this argument holds for single stock futures.I would say that this is still generally true however things have changed a bit. If you are going to trade the index, futures will always be more cost efficient however today a large constituent (index member) or even an index sub-sector can lead or push the basket with news or even at times a market participant taking on a position. Spreads and margins have gotten tighter so while it is still expensive to trade indexes via equities the equities can, at times, lead. Things are so tight that it goes back and forth. Correlation is very close across the broader markets so things will shake around a bit.What happened to the old "cash is king"?I would love to hear more sharing about this topic in general and my question in particular.Thank a bunch men.