Assume I want to buy some DEC 2013 QM if oil prices crash this summer because I think oil makes a big recovery next year due to inflation and a potential strike on Iran. I want to buy QM rather than CL because it gives me more control over leverage. Now QM Dec 2013 currently has NO BID or OFFER even though the equivalent CL contract is pretty liquid. But this lack of liquidity in QM is actually an ILLUSION because if you create an even small arb. opportunity with the equivalent CL contract then you can buy and sell all the contracts you want at competitive prices. So there is a vast amount of UNDISPLAYED HIDDEN LIQUIDITY out there waiting for an arb opportunity. So if I buy some QM today at 90 then as I'm sleeping someone posts a bid for 100 contracts at $5 and some untested bot recently programmed by an amateur mistakes the bid for an offer and sells one contract at $5. Then will the IB auto-liquidation engine kick in and sell my whole position at market at $5 wiping me out even though I could have easily gotten out at around 90 if I had created a small arb opportunity with CL? Or if there is a bid at $5 and an offer at $92 will IB calculate the price at the midpoint of around 51 and liquidate the position? Its hard to know exactly what would happen since there is no document that specifies exactly how this liquidation engine works.