2006至2007年，木材产品巨头惠好公司（Weyerhaeuser）斥资8亿美元，进行了公司历史上最大规模的股票回购。当时，其股价飙升至每股80美元的历史最高值。而在2009年，其股价跌至每股30美元，当时公司只花了200万美元用于股票回购。同样，2007年，半导体设备生产商美商休斯电子材料公司（MEMC Electronic Materials）斥资1亿美元，在其股价达到每股90美元的最高价时，回购公司股票。目前，其股价为每股8美元，而该公司没有任何要回购股票的迹象。还有一个更极端的例子：在过去十年中，花旗集团（Citigroup）投入310亿美元，用于股票回购，结果其股票价格下跌了97%。最后，花旗集团不得不求助政府，提供450亿美元的注资。

    我们不妨称其为另一个泡沫：2004至2008年间，许多公司资金充裕、信心高涨，总计投入了1.8万亿美元，以回购价格不断飙升的股票。而当市场崩溃时，这些公司又是怎么做的呢？它们没有充分利用股票价格优势，继续回购股票，而是停止了回购，这显然不是明智的投资者应有之举。下图显示了这些公司的回购行为与市场走势之间的紧密联系，他们的回购显然属于决策失误。

    现在，回购再一次接近历史记录水平，这一趋势具有一定的参考价值。知名投资机构毕润宜公司（Birinyi Associates）表示，到六月中旬，美国公司宣布用于回购股票的资金已经高达2,730亿美元，回购规模之大排在历史第三位。

    按理说，公司回购股票时，投资者将从中获利。发行在外的股票越少，意味着每股应占的利润越多，股票价格也就越高。而且，公司比任何人都更清楚自身的发展前景，如果连公司都在买入，这应该是一个好迹象吧？可惜这几年的事实并非如此。

    事实上，投资者不应把股票回购本身当作买进的信号。公司回购股票的原因是多种多样的，比如清理授予高管的额外股票，或管理层认为股票估值过低，总之，只有少数原因会产生积极的结果。

    In 2006 and 2007 timber giant Weyerhaeuser (WY) conducted one of the biggest share buybacks in its history. It unleashed $800 million to purchase its shares, which were dancing near an all-time high of $80. In 2009, with the stock at $30, the company spent a mere $2 million on its own stock. Similarly, semiconductor equipment maker MEMC Electronic Materials (WFR) purchased $100 million of its shares near their peak of $90 in 2007. Today the shares are trading at $8, and MEMC shows no signs that it's buying. Then there's the ultimate horror story: Citigroup (C) spent $31 billion last decade on its own stock, only to see it crash 97%. Citi then needed $45 billion in infusions from the government.

    Call it the other bubble: From 2004 to 2008 companies flush with cash and confidence spent $1.8 trillion on their own soaring shares. When the market collapsed, what did they do? Rather than take advantage of discount share prices, as wise investors are supposed to do, they stopped buying. Indeed, the chart below illustrates just how closely share buybacks track the markets, when they should be doing the opposite.

    That's newly relevant because buybacks are again reaching record levels. U.S. companies have announced $273 billion in stock repurchases through mid-June, says Birinyi Associates, on pace for the third-largest year ever.

    In theory, investors should benefit when companies acquire their own stock. Fewer shares outstanding means larger profits per share and thus a higher stock price. And if the company, which knows its prospects better than anyone, is buying, that's a good sign, right? Alas, in recent years it often hasn't worked out that way.

    Indeed, investors shouldn't treat a repurchase on its own as a signal to buy. Companies announce buybacks for many reasons -- among others, to mop up the extra shares issued to executives or because management thinks shares are undervalued -- and only some have positive implications.

    投资研究公司TrimTabs Investment Research的CEO查尔斯•彼得曼表示，现在的回购会深深地刺痛投资者。他说：“现在情况有点反常”。即使回购能够升值，高管也不会把自己的资金用于公司股票回购。六月中旬的内部人员回购额几乎达到2009年的回购总额，而2009年的回购总额仅是2007年的四分之一。彼得曼说：“这表明许多公司现金充裕，它们认为现金和公司的业务没有太大关系。所以，它们支持股票价格，并开始回购股票，这也正是华尔街希望它们做的。”

    那么，结果是，公司也容易犯和个人投资者相同的错误。顾问公司Fortuna Advisors的格雷格•米兰说：“真正的问题不是回购股票的行为。而是时机问题。”公司在商业周期的巅峰期拥有最多资金，这也是其股价攀至最高的时候，然后他们以高价买入结束一个商业周期。他说：“首先，公司把资金用于好的投资项目；其次，进行并购；再次，偿还债务。最后，才会用于股票回购。”

    有些公司在回购游戏中显然比其他公司做得更出色。Fortuna Advisors曾经对标准普尔（S&P）500强公司过去10年的股票回购进行调查，将回购时的股票价格与现在的股票价格进行对比，以计算出理论上的“回购回报率”。

    Fortuna的数据显示，最大的赢家是美国在线旅游公司Priceline.com。2006年，该公司投入1.3亿美元用于回购股票。后来，该公司的欧洲业务大幅上升，令分析师震惊，股票价格也上涨至原来的三倍；其第二次回购也收效颇丰。总体来看，Princeline的回购带来了大约1,013%的回报。相比之下，过去十年标准普尔500强公司的年平均回购回报率仅为6.3%（数字来源：Fortuna）——尚不足以填补用于购买股票的费用。

    那么，在新一轮的回购热潮中，投资者应该怎么做呢？这个问题看上去好像很简单。市盈率以及其它显示公司高管正在为他们的投资组合买入股票的传统衡量方式都值得参考，但是除此以外，最好把回购也看作是一条有用的信息。按此标准，摩根大通银行（J.P. Morgan Chase）和富国银行（Wells Fargo）的股票看起来极具吸引力。这两家银行的回购计划都位居2011年十大回购计划之列，内部人员的股票回购额超过了它们的股票销售额。对于摩根大通银行，新法规令投资者担忧，但是这家投行保守的资金水平和稳定的股本回报率令其颇具吸引力，特别是其7倍的预测市盈率，处于一个较低的水平。而对于富国银行，它无需遵守可能影响其他银行的自由资金交易业务法规，而且其贷款拖欠或止赎率仅为美国银行（Bank of America）的一半。

    另外，两家拥有良好回购记录的公司今年也宣布了回购计划。美国快捷药方公司（Express Scripts）是一家药房福利管理公司，名列Fortuna调查结果第15位，该公司计划斥资17亿美元用于公司股票回购。铁路运营商联合太平洋铁路公司（Union Pacific）因为提高基本运价，上季度销售额增加了13%，该公司计划在2014年前回购4,000万支公司股票。以销售额增加和稳健的基本面为依托的股票回购，才能获得良好回报。以上两家公司的回购就符合这样的条件。

    （翻译 乔树静）

    Today's buybacks could very well bite investors, argues Charles Biderman, CEO of TrimTabs Investment Research. "We have an anomaly right now," he says. Even as buybacks proliferate, executives aren't spending their own money on their company's shares. Insider purchases through mid-June were on track to trail even 2009's total, which itself was just a quarter of the purchases made in 2007. "That indicates to me that companies are flush with cash, and don't feel they have anything to do with the cash in terms of their business," Biderman says. "So they are supporting their stock price, doing what the Street wants them to do, which is buying back shares."

    Companies, it turns out, are prone to the same mistake individual investors make. Says Greg Milano of Fortuna Advisors: "The real problem is not the act of buying back stock. It's the timing." Companies have the most money at the top of the business cycle, when their share price is peaking, and they wind up buying high. "Companies spend first on making good investments," he says, "then acquisitions, then they pay down debt. Only after all that do they buy back stock."

    That said, some companies are clearly better than others at this particular game. Fortuna Advisors has tallied buybacks at S&P 500 companies over the past 10 years, comparing the price at the time of repurchase with today's stock price to calculate a theoretical "return on buyback" figure.

    The biggest winner: travel website Priceline.com. (PCLN) In 2006 it spent $130 million on its own shares before its booming European business caught analysts by surprise and the stock tripled; a second repurchase also paid off. Overall Priceline's buybacks have generated an estimated 1,013% gain. By comparison, the average S&P 500 company's annualized return on buybacks over the past decade was 6.3%, according to Fortuna -- not even enough to cover the cost of capital needed to pay for the shares.

    So how should investors play the new buyback boom? It may seem obvious, but repurchases are best viewed as one useful item of information to be weighed along with traditional metrics, such as price/earnings ratios or indications that company executives are buying the stock for their own portfolios. By that standard, shares of J.P. Morgan Chase (JPM) and Wells Fargo (WFC) look appealing. Repurchase plans at the two banks rank among the 10 largest of 2011, and insider buying exceeds selling at both banks. With JPM, new regulations have scared investors, but its conservative capital levels and solid return on equity make it attractive, especially at its anemic 7 forward P/E. For its part, Wells faces none of the proprietary-trading regulations that could hamper other banks, and its percentage of mortgages in delinquency or foreclosure is about half that at Bank of America (BAC).

    Two companies with strong buyback records have also announced repurchases this year. Express Scripts (ESRX), the pharmacy benefit manager, ranked 15th in Fortuna's study and expects to spend $1.7 billion on purchases. Railroad operator Union Pacific (UNP), whose sales rose 13% in the last quarter because it was able to raise freight prices, plans to acquire 40 million shares by 2014. It's that sort of buyback -- one accompanied by rising sales and strong fundamentals -- that can put a stock on track for a good return.