For the large traders looking for ETF liquidity: IB's prop side, Timber Hill now makes markets in the ETF's in block trading sizes (10,000 shares or mkt value greater than $2 milion). Sizes can be from 10K shares to 500K shares. Markets will be made from 8 AM - 5 PM. If there is interest, send me an e-mail or PM. I can provide indications of widths, costs, clearing info and a contact number on our prop desk. You do not have to be an IB customer to particpate.