上上周五，CNBC电视频道主播拉里•库德罗在谈及日本大地震时不慎失言，冒出了一句事后看来极不应该的话：“此次(灾难导致的)死亡人数看来要比(灾难带来的)经济冲击严重得多，对此我们应该感到庆幸。”这番被视为极度缺乏同情心的言论一经播出，舆论哗然，虽然他紧接着说的是“当然，如此高的死亡人数确实让人悲恸。”

    在这个网络舆论影响力不容忽视的Twitter时代，他很快就被迫致歉。如果当时他说话更谨慎一些，这些逢迎附会、自以为是的同情心就不会有机会，但他的话的确揭露了一个投资的真相。那就是，优秀的投资者绝不会让情感——无论是积极的，还是消极的——左右他们买入、卖出或持有的决定。言归正传：随着日经指数（Nikkei）在大地震后直线下跌——尽管上周有一个交易日反弹近6%，眼下是精明的投资者入市并买入的时机吗？

    曾长期担任摩根士丹利（Morgan Stanley）策略师、现为对冲基金投资者的巴腾•比格斯于上周二晚些时候表示，他认为导致日经指数下跌16%的恐慌性抛盘是“明显的过度反应”，现在是时候抓住这把下落的尖刀了。

    Jefferies全球固定收益策略主管戴维•泽尔沃斯在给投资者的报告中也表达了相似的观点，“我不认为现在有很多日本政策制定者（或市场参与者）都相信日本的‘长期’前景如此黯淡，以至于股票估值应该只比2003年年中或 2009年年初略高几个百分点。”言下之意：现在是买入的时候了。

    如果你在此次大地震前的几周或几个月已开始逐步买入日本股票，现在肯定懊恼不已。我注意到在震前，有些机构分析师已在邮件中透露出对日本股市的乐观情绪，最近的是在2月末。但如果你认为这些观点有道理——即当时我们对日本经济的看法已到了悲观得不能再悲观的地步，如果你愿意押注、相信此次大灾难带来的核辐射及其他影响不会像很多人认为的那样严重，那么现在就是更好的买入时机。

    [想想漏油事件刚曝光后的英国石油（BP）股票——十年来最佳的买入机会。别跟我胡扯说什么支持英国石油、所以买它的股票。二级市场买入讲的是战术，而不是支持或不支持一家公司和一个行业。如果你不明白这一点，趁早金盆洗手，安安心心坐在摇椅上看你的电视吧。]

    而且，在这一片黯然中也仍有一丝光亮。日本教授东浩纪在上周四的《纽约时报》（New York Times）上就写到了日本迅速上升的民族自豪感，相信日本有能力应对这次空前的大灾难。或许日本走出此次大灾难后，会比近几十年来更为自信？

    不过，现在仍很难讲，不是吗？但预测未来总是很难。我的老朋友、CNNMoney的保罗•莫尼卡最近撰写的一篇专栏文章通过一分为二的分析，对此有精准阐述：机构投资者不能(就下一步做什么)达成一致。但这就是关键所在，不是么？如果每个人的观点都一致，就很难挣钱。

    谁知道这场核灾难会如何演变？日本经济真的能走出这又一次重创吗？但正是在市场急速转向的时候，才是真正赚钱或亏钱的时候。我？我已经入市了。

    Speaking about the earthquake in Japan on CNBC last Friday, anchor Larry Kudlow put his foot quite deeply into his mouth. "The human toll here looks to be much worse than the economic toll and we can be grateful for that," he said. He was quickly skewered for what was seen as a profound lack of compassion, despite the fact that the next words out of his mouth were, "and the human toll is a tragedy, we know that."

    This being the age of the angry mob on Twitter, he was soon forced to issue an apology. And while he should have known better than provide an opportunity for obsequious and self-righteous compassion, his remark did point to a fundamental truth of investing. That is, the best investors don't let emotions -- positive or negative -- color their decision to buy, sell, or hold. To the point: with the Nikkei in free fall after the devastating earthquake -- notwithstanding the one-day bounce of nearly 6% this week -- is it time for savvy investors to step in and buy?

    Barton Biggs, the long-time Morgan Stanley strategist turned hedge fund investor, said late Tuesday that he thought the panic selling that sent the Nikkei down 16% was "a gross overreaction" and that it was time to try and catch that falling knife.

    David Zervos, head of global fixed income strategy at Jefferies, wrote of a similar sentiment in a note to investors. "I do not believe that there are many Japanese policy makers (or market participants) who believe the 'long term' prospects for Japan are so dim that we should be at equity valuations which are only a few percentage points from the levels reached in mid 2003 or early 2009," he said. Translation: it's time to buy something.

    You'd hate to be the guy who was warming up to Japanese stocks in the weeks or months before this earthquake. I'd noticed several instances of optimism about Japanese stocks in missives from institutional analysts as recently as late February. But if the arguments made sense to you then -- that we'd reached the so-called moment of maximum pessimism about the Japanese economy -- and you're willing to take the bet that the fallout, both nuclear and otherwise, from recent events isn't going to be as severe as many appear to believe, then now is an even better time to buy.

    (Think of BP (BP) stock right after the spill -- best buying opportunity in a decade. And don't give me any guff about supporting BP by buying its shares. Secondary market buying is about tactics, not support or lack thereof for a company or industry. If you don't get that, hang up your investing spurs, settle into your rocking chair, and watch the show.)

    There might even be a silver lining to this whole mess. In Thursday's New York Times, Hiroki Azuma, a Japanese professor, writes of a burgeoning national pride in Japan's ability to deal with this greatest of disasters. Might the country emerge from it more confident than it has been in recent decades?

    Still, it's a tough call to make, isn't it? But predicting the future always has been. A recent on-the-one-hand, but on-the-other column by my old buddy, CNNMoney's Paul La Monica, showed that precisely: institutional investors can't reach consensus about what to do next. But that's the point, isn't it? It's pretty hard to make money when everyone agrees on something.

    Who knows what will happen with the unfolding nuclear disaster? Or whether Japan's economy really can bounce back from yet another punch in the gut. But it's at sharp turns in the market where the real money is made or lost. Me? I'm in.