U.S. stocks have rather shockingly been the best performers among all G-20 stocks in the past year, FT Alphaville noted yesterday.

英国《金融时报》（FT）旗下专业财经新闻评论网站FTAlphaville 11月2日撰文指出，去年在G20各成员国的股市中，美国股市的表现最好，这着实出人意料。

But investors have also had to endure a scary ride to get that performance - scarier even than the traditionally wild and woolly emerging market of China, by one measure.

但想要从表现最好的美股中获益，投资者也得担惊受怕一回。按某种指标衡量，其波动程度甚至比历来波动剧烈的中国股市还要大。

That's according to Bespoke Investment Group, which notes today that the S&P 500's rolling 50-day average daily percentage change is 1.6%, compared with just 1% for the Shanghai Composite.

我这么说并非空穴来风：Bespoke Investment Group11月2日撰文指出，标准普尔500指数50日移动平均线每日波动幅度为正负1.6%，相比之下上证综指的波动幅度只有正负1%。

Typically Shanghai's rolling rate of change is higher than the S&P 500's, but S&P volatility has spiked above Shanghai's three times in the past few years