It is often said that something occurring once is a fluke and twice is a coincidence. But three times marks a trend. Considering this old adage, the bulls have to like what they're seeing.

Three high-profile investors have touted stocks this week, with the latest praise coming from Warren Buffett. In an article posted on Fortune's website, the billionaire investor says stocks are a more attractive long-term investment than gold or bonds.

'I believe that over any extended period of time this category of investing will prove to be the runawaywinner among the three we've examined,' he says. 'More important, it will be by far the safest.'

Buffett has a history of praising stocks, so today's letter isn't exactly a revelation. But the timing coincides with what others have been saying.

Buffett joins the notoriously-bearish Nouriel Roubini and BlackRock CEO Larry Fink as bigwig investors who have praised stocks. Roubini, nicknamed Dr. Doom for accurately forecasting the 2008 financial crisis, thinks the rally has legs and can continue through the first half of the year.

Roubini isn't totally bullish. His firm still has a year-end S&P 500 price target of 1,300, meaning he thinks stocks will end the year lower than they are now. But the fact that Roubini isn't pushing a doomsday scenario is, itself, bullish.

BlackRock's Fink says the current environment is so favorable for risky assets that people should be 100% invested in stocks. No questions asked.

As all this optimism bubbles, the cynics inside us at MarketBeat wonder whether the contrarian view will take place sooner than later. When bullish sentiment starts running rampant and many folks start believing the same thing, that's typically the sign of a top.

The bullish case for equities is well documented. The Fed's near-zero interest rate policy isn't going away anytime soon and more accommodative measures could be on the horizon, which should continue pushing investors toward riskier assets.

Valuations still aren't expensive, the economy is improving and dividend-paying stocks are the way to stay safe but remain in equities. The list drags on.

The stars are aligning for the rally to continue.

But when the evidence for additional gains looks so obvious, it is often the moment when the market will do the opposite and surprise everyone.

As UBS' Art Cashin like to say, 'stay alert, stay nimble.'

Steven Russolillo

• attractive [ə´træktiv] a.有吸引力；诱人的 (初中英语单词)
• investment [in´vestmənt] n.投资；(时间等)投入 (初中英语单词)
• financial [fi´nænʃəl] a.金融的，财政的 (初中英语单词)
• favorable [´feivərəbəl] a.赞成的；顺利的 (初中英语单词)
• sentiment [´sentimənt] n.情绪；多愁善感 (初中英语单词)
• running [´rʌniŋ] a.奔跑的；流动的 (初中英语单词)
• anytime [´enitaim] ad.无论什么时候 (初中英语单词)
• horizon [hə´raizən] n.地平线；范围；视野 (初中英语单词)
• expensive [ik´spensiv] a.费钱的，昂贵的 (初中英语单词)
• economy [i´kɔnəmi] n.经济；机制；组织 (初中英语单词)
• additional [ə´diʃənəl] a.附加的，额外的 (初中英语单词)
• obvious [´ɔbviəs] a.明显的；显而易见的 (初中英语单词)
• revelation [,revə´leiʃən] n.展现；揭露(的事物) (高中英语单词)
• crisis [´kraisis] n.转折点；危机 (高中英语单词)
• environment [in´vaiərənmənt] n.郊区；周围；条件 (高中英语单词)
• coincidence [kəu´insidəns] n.巧合；符合；一致 (英语四级单词)
• considering [kən´sidəriŋ] prep.就...而论 (英语四级单词)
• warren [´wɔrən] n.养兔场；大杂院 (英语四级单词)
• winner [´winə] n.胜利者，得奖者 (英语四级单词)
• accurately [´ækjuritli] ad.准确地；精密地 (英语四级单词)
• totally [´təutəli] ad.统统，完全 (英语四级单词)
• policy [´pɔlisi] n.政策；权谋；保险单 (英语四级单词)
• investor [in´vestə] n.投资者 (英语六级单词)
• extended [iks´tendid] a.伸长的；广大的 (英语六级单词)
• category [´kætigəri] n.种类；部属；范畴 (英语六级单词)
• runaway [´rʌnəwei] n.逃跑(者) a.逃亡的 (英语六级单词)