This market lacks a tradeable flow of buy bids versus versus ask bids. There is not enough liquidity to support sell volumes. Yesterday they had to halt the markets informally. The market has problems right now. I wouldn't be placing market orders on either side of a trade right now. You must place limit prices on everything. Would not be surprised to see another 2008/09 type avalanche back to the March 09 lows. Remember they have not fixed the banks, they are loaded with non-performing debt, and the accounting rules were changed so they don't have to write it off.