The majority of futures and options traders (maybe 90% or so?) have switched from open-outcry pit trading to electronic trading. I know many individual traders and institutions do still trade in the pits because that's where they're more comfortable and used to, or because the pit traded market for their derivative has more volume, but I would have thought that would only be a small few.

However listening to pit audio (from Traderaudio.com and Tradethenews.com), I still often here them talking about institutional buyers such as J. P. Morgan, Morgan Stanley, Smith Barney, ect. trading big lots (50-250 lots sometimes) in the pits (specifically the S&P 500 pit).

I'm assuming the majority of their trading is electronic but still a bit curious why they still trade at all in the open-outcry pits.