来自《耶鲁大学开放课程：金融市场第7集第7集》

but, I think that you get the impression

但我想你们应该会发现
that there's something possibly wrong here with efficient markets

有效市场假说有可能出错了
because the red line is just a smooth growth path

因为这条红线上涨得十分平稳
like nothing happens to it

就像没有任何事件冲击
and yet the stock market is going up and down all over the place.

而股市却是一直起起落落
It's a little bit like if you had a weather forecaster

这就有点像是有一个气象预报员
and this morning he says,

他今天早上预报说
I predict today that the low today will be -100o

预计今天最低温度为零下100度
and then two days later he says,

而过了两天又预报说
I predict that the low today will be +150o.

预计今天的最低气温将为150度
You would eventually start concluding

你立马就能得出
that this weather forecaster can't be trusted

这气象预报不可信的结论