《How To Know When To Sell An Overvalued Stock | FAST Graphs》
尽管公司业绩良好，UNP 在高估值下持有风险较高，因波动性及可能跑输大盘。
然后是 Union Pacific。一旦它变得高估，你持有它就会经历几乎赚不到钱的时期，但随后你又有了这波上涨。但问题是，你在心理上是否足够适合或足够强大，能够承受这种波动并舒适地持有这只股票？
归根结底，在这些高估值下你承担了大量风险。你承担的风险是，即使公司表现良好，你也不会。
Then here's Union Pacific. Once it got overvalued, you're holding it through periods where you'd have made almost no money, but then you had this rally again. But the question is, are you psychologically fit or strong enough to take this kind of volatility and be able to hold the stock comfortably? Bottom line is you're taking a lot of risk at these high valuations. You're taking a risk that even if the company does good, you won't.