One-minute plunge sends Chinese shares down by 10%

Unexplained drop follows similar move in Hong Kong this month

The China Financial Futures Exchange is investigating the tumble (Tomohiro Ohsumi/Bloomberg via Getty Images)

Chinese stock-index futures plunged by the daily limit before snapping back in less than a minute, the second sudden swing to rattle traders this month.

Contracts on the CSI 300 Index dropped as much as 10 per cent at 10.42 a.m. local time, recovering almost all of the losses in the same minute.

More than 1,500 June contracts changed hands in that period, the most all day, according to data compiled by Bloomberg.

(Bloomverg (Bloomverg)

The China Financial Futures Exchange is investigating the tumble, said people familiar with the matter, who asked not to be named because they aren’t authorized to speak publicly.

The swing follows a similarly unexplained drop in Hang Seng China Enterprises Index futures in Hong Kong on May 16, a move that heightened anxiety among investors facing slower Chinese economic growth and a weakening yuan.

Volume in China’s stock-index futures market, which was the world’s most active as recently as July, has all but dried up after authorities clamped down on what they deemed excessive speculation during the nation’s $5 trillion equity crash last summer. Tuesday’s volatility had little impact on the underlying CSI 300, which rose 3 per cent.

“Liquidity in the market is really thin at the moment,” Fang Shisheng, Shanghai-based vice general manager at Orient Securities Futures Co., said by phone. “So the market will very likely see big swings if a big order comes in. The order looks like it’s from a hedger.”

An official at the China Financial Futures Exchange in Shanghai said he couldn’t comment and refused to give his name.

Chinese policy makers restricted activity in the futures market last summer because selling the contracts is one of the easiest ways for investors to make large wagers against stocks. Volumes shrank by more than 90 per cent from their peak after officials raised margin requirements, tightened position limits and started a police probe into bearish wagers.

Some international traders with negative views on Chinese stocks have shifted to offshore markets to bet against them. Short interest in one of the largest Hong Kong exchange-traded funds tracking mainland shares has surged fivefold this month to its highest level in a year, according to data compiled by Markit and Bloomberg.

The CSI 300 has dropped 15 per cent this year, versus a 2.2 per cent gain in the MSCI Emerging Markets Index.

While sudden price swings are hardly unique to Chinese exchanges, the country’s markets have come under increased scrutiny in recent months as MSCI Inc. considers adding mainland shares to its international indexes. Recent measures to curb trading halts and clarify beneficial ownership rules have improved the country’s odds of inclusion to 70 per cent, Goldman Sachs analysts wrote in a report, one of the factors behind the Tuesday’s rally. MSCI will announce its decision next month.

© 2016 Bloomberg L.P