It should be an enormous advantage for investors in stocks to have those wildly fluctuating valuations placed on their holdings – and for some investors, it is. After all, if a moody fellow with a farm bordering my property yelled out a price every day to me at which he would either buy my farm or sell me his – and those prices varied widely over short periods of time depending on his mental state – how in the world could I be other than benefited by his erratic behavior? If his daily shout-out was ridiculously low, and I had some spare cash, I would buy his farm. If the number he yelled was absurdly high, I could either sell to him or just go on farming. 

对股票投资者来说，股价大幅波动按说应该是个巨大的优势。实际上，对一部分投资者来说确实如此。毕竟，如果一个与我相邻的农场主，这家伙情绪忽高忽低，每天给我出个报价，要么买我的，要么把他的卖给我；这些价格短期波动巨大，取决于他的情绪。我怎么可能不从他古怪的行为中受益呢？如果他报价低得荒唐，而我有一些闲钱，我会买下他的农场。如果他喊的数字高得离谱，我要么卖给他，要么种我的地不理他。

Owners of stocks, however, too often let the capricious and often irrational behavior of their fellow owners cause them to behave irrationally as well. Because there is so much chatter about markets, the economy, interest rates, price behavior of stocks, etc., some investors believe it is important to listen to pundits – and, worse yet, important to consider acting upon their comments. 

然而，股民经常被其他股民的情绪和非理性行为带动着，自己也变得不理性。因为有太多关于市场、经济、利率、股价走势的说法，一些投资者认为听取股评家的评论很重要，更糟糕是，他们认为参照股评炒股也很重要。

A “flash crash” or some other extreme market fluctuation can’t hurt an investor any more than an erratic and mouthy neighbor can hurt my farm investment. Indeed, tumbling markets can be helpful to the true investor if he has cash available when prices get far out of line with values. A climate of fear is your friend when investing; a euphoric world is your enemy.

就像一个整天忽高忽低报价的邻居不会伤害我的农场投资一样，股价崩盘或其他极端的市场波动不会伤害股票投资者。事实上，当价格远低于价值时，如果真正的投资者手里有闲钱，市场暴跌对他有利。投资时，愁云密布的熊市是你的朋友；皆大欢喜的牛市是你的敌人。