Overnight trading between Monday and Tuesday was a worrying time for those involved in the CSI 300 Index futures contract. The sudden slump from 3,130 points to 2,730 – and all the way back up again – acts as a warning of what can happen in thin markets. Someone wanted to sell a few contracts and panicked when they found no bids on the way down. Strong nerves are needed in cases like this as more often than not professionals quickly spot the problem and sort it. The rebound reinforces important support between 2,700 and 2,800 points, the lows in August last year, January and February this year, and this week. With resistance seen at 3,175, expect a drift back down again.