1月4日是熔断机制生效的首个交易日，就发挥了功效，13点28分，沪深300指数下跌7.02%，市场暂停交易至收盘。

Trading on the Shanghai and Shenzhen stock markets was ended at 1:28 p.m. Monday after shares tumbled 7 percent, triggering the new "circuit breaker" mechanism on the first trading day of 2016.

The early end to trading, the first in the history of China's stock markets, coincided with the launch of the circuit breaker, designed to contain wild swings in the markets.

13点13分，沪深300指数跌5%，达到第一档熔断阀值，暂停交易15分钟。13点28分，股市继续交易，五分钟后，沪深指数下跌7.02％，暂停交易至收盘。截至熔断收盘，沪指跌6.85%，深圳成指跌8.16%，创业板指跌8.21%。

At 1:13 p.m., trading was suspended for 15 minutes and, immediately on reopening at 1:28 p.m., the index fell a further 2 percent and trading ceased. When trading closed, the Shanghai Composite Index was down 6.85 percent, the smaller Shenzhen index down 8.16 percent, and the ChiNext Index, China's NASDAQ-style board of growth enterprises, down 8.21 percent.

中国制造业运行继续放缓，人民币汇率走势大跌是造成此次沪深300暴跌的重要原因。

The slump is generally being attributed to weaker than expected manufacturing activity in December and a steep fall in the yuan exchange rate.

1月4日上午，财新PMI数据公布，2015年12月中国财新制造业PMI录得48.2，较11月的48.2略有回落。

The Caixin General China Manufacturing Purchasing Managers' Index (PMI) released Monday, edged down to 48.2 in December from 48.6 in November.

中国外汇交易中心的最新数据显示，4日人民币对美元汇率中间价报6.5032，较前一交易日下跌96个基点。

The central parity rate of the yuan, weakened by 96 basis points to 6.5032 against the U.S. dollar on Monday, according to the China Foreign Exchange Trading System.

什么是熔断？

根据熔断规定，当沪深300指数当日涨跌幅达5%时，将触发熔断机制，暂停交易15分钟;当沪深300指数当日涨跌幅达7%时，暂停交易直至收盘。

The mechanism follows the Hushen 300 Index, which reflects the performance of both Shanghai and Shenzhen traded stocks. When the index rises or falls by 5 percent, the circuit breaker imposes a 15-minute suspension in trading. If the Hushen 300 declines by over 7 percent, trading is terminated for the day.