On Tuesday, stocks put in a choppy and ultimately weak session. Major share indexes worsened with Shanghai and Shenzhen Composite down 0.79% and 0.62% respectively yesterday. In addition, trading volume on both markets shrank a bit.

Investors seemed worried as a growing number of issues crashed sharply. Worse still, some stocks, such as, BEIKEN and Red Wall just crashed without any reason.

Our sense is that it should not be an individual problem. Something must go wrong. If no targeted measures are given, it could take toll on more stocks.

In our view, investors should pay attention to central banks' next move. If more clues can be found to inject money into the market, investors would be more relieved.

Technically, if Shanghai Composite dips below 3190 points today, it might be time for heavyweight investors to cut some positions.

(Zheng Buchun is NBD's Columnist)

Email: tanyuhan@nbd.com.cn