China major stock indexes collapsed on Monday morning, with traders saying market disappointment over the lack of a liquidity move by the central bank during the weekend triggered a fresh selloff. The worry was aggravated by a strong injection of short-term liquidity into the interbank market that many read as a substitute for deeper easing. China CSI300 stock index futures for September fell 7.1 percent, to 3,233.6, or 109.37 points below the current value of the underlying index, and all other futures contracts were also negative.