There is no numerically specific definition of a crash but the term commonly applies to steep double-digit percentage losses in a stock market index over a period of several days.

股市崩溃在数字上没有具体的规定，不过这一名词一般适用于股票市场指数在几天之内跌去两成甚或更多的情况。

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That's because the managers of active stock funds have raised their cash levels to an average of nearly 6% of assets, while index funds always keep all their assets in the market.

这是因为活跃的股票型基金的经理已经将从总资产中提出了6%的现金流，而指数基金的所有资产仍然在市场上。

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PetroChina's stunning debut on the Shanghai stock Exchange again demonstrated the force of China's bull market, which has more than doubled its benchmark stock index so far this year.

中国石油在上海证券交易所首日上市令人震惊的表现再次显示了中国牛市的力量，今年以来中国股市已经上涨了一倍多。

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If you want to play it safe, one smart choice would be to buy the Vanguard Total World Stock Index Fund, which, as the name implies, tracks an index of the global stock market.

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In fact the 100 share index, the main measure of stock market value, ended the year higher than it had started.

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In recent days, the VIX Index, a measure of expected stock market volatility has been double the historic norm.

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