有些股票被認為未來的價值一定會高於現在的買入價格，對這類股票進行投資即稱為“價值”投資。股票的價值是通過公司提交的有形資產淨值、每股收益、股息支付等進行評估的。因此，價值投資者都偏愛市淨率低、市盈率高、股息率高的股票。
但是滿足這些條件的股票風險都很高，股票很便宜可能是因為公司瀕臨破產，而不是單純的價格便宜。想要區分真便宜還是假便宜（價值陷阱）可不容易，以下幾點可以幫助你進行區分。
1. 因公司欺詐導致價格下跌的股票要敬而遠之。比如安然公司(Enron)，世通公司(WorldCom)，美國泰科(Tyco)都因為爆出醜聞而股價暴跌，這種情況可不是單純的價格便宜。最終，他們的走勢趨近於0，讓他們的股東兩手空空。
一旦涉及欺詐，財務報表中的數據再無用處，而此時根本無法正確的評估公司的價值。嚴重點說，一旦涉及欺詐，尚未被公司管理層貪污的那部分也變得一文不值。涉及欺詐的股票一定不要沾手。
2. 公司高管對前景過分樂觀的要小心。任何公司承諾的持續的兩位數增長都是不現實的，一旦他們如此承諾，而又不能兌現時，管理層就會捏造數據。沃倫·巴菲特(Warren Buffett)在20世紀80年代買入了房地美(Freddie Mac)的股票，那時股價非常之低。20世紀90年代，他在獲利27.5億美元時果斷平倉，因為他發現公司高管對發展前景的預估過於樂觀。
3. 高負債、高槓桿的公司要避開。負債是一把雙刃劍。在好的時機下，你可以利用槓桿賺取很多錢，而借錢也很容易。若時機不好，你可能一下子賠光，這是你最想借錢的時候，信用商反而開始催你還錢。
計算好安全系數以確保公司的收益足夠償還債務，尋找利息保障倍數在2-4倍的公司（息稅前利潤至少是支付利息的2-4倍）。上限要適用於行業狀況，尤其是週期性行業；下限要適用於更穩定的收入，例如公共事業。
沒有債務的公司很難破產，除非遇到飛來橫禍（例如大量不利於它的法律決策），或是產品太貴賣不出去無法回本（在損益表中淨收益顯示為負）。另一方面，槓桿太高也可能摧毀一家好公司。
4. 產品、服務過時的公司要避開。百視達(Blockbuster)就是個很好的例子，在所有人在家點點鼠標就能下載的年代，誰還會去實體店裡買影碟？同樣地，隨著互聯網的擴展，報紙和實體書店都收到了巨大的沖擊。過時的服務和產品意味著現在的損失會延續下去，其股價可能沒有反彈的餘地了。
5. 競争者越來越多的公司要小心。查看公司五到十年利潤率（淨收益除以收入），同該行業的其它公司向對比，如果利潤率逐年下降，就意味著他們為了維持客戶必須提供更有競争力的價格，從而導致收益降低。如果公司在價格上也沒有競争力，估價再低也不要選它。
6. 高度監管行業的公司要當心。以美國為例，他們的管理費用很高，很多公司紛紛將公司轉移至中國或是其他國家。很多產品都不再是美國制造了。發薪日貸款是另一個例子，借出100美金，兩到三週内到期，需支付20美金的利息，這是暴利。然而政府規定年化利率不得超過36%，大大削減了利潤。
7. 因削減股息導致股價下跌的股票要小心，尤其是公司根本不打算恢複股息的時候。削減股息通常意味著公司可用來支付的收益減少了，削減股息導致的價格修正是曠日持久的。股價大幅下跌會將其内在價值降低至50%甚至更低，除非估價十分吸引人，否則就別買。
8. 專家們的預估往往是很寬泛的。在收益公佈之前，他們總是往少了說。公司的實際收益超過了專家的預測，這樣面子上很好看。專家們偶爾會對股價反應過度從而導致預測失誤，這就是“趁低吸納”的主要原因，但是預測失誤是個不詳的徵兆。
9. 只投資盈利企業。分析企業五年來的損益表（十年的更好）。在五到十年中，持續盈利的公司的每股收益或多或少都會有所增漲。若公司的收益連續幾年都有下降，那多少錢買入都嫌貴。
10. 尋找内部購買的機會。内部人員最清楚他們公司的實際價值，如果股價確實很便宜，員工們也會參與購買。内部人員購買股票只有一個原因：他們知道股票會上漲。另一方面，如果你發現好多内部員工都在賣出股票，這是一個不詳的預兆，你就不應該再考慮這支股票了。
11. 從資產負債表中分析公司是否健康。查看公司的流動資產比查看它的流動負債更為重要，因為流動資產可以確保他們的短期支付能力。更重要的是減去庫存（可能是非現金）以計算其速動資產淨值並從流動資產中計算出流動負債總額。此外,用流動負債總額除以流動資產總額（少庫存）以確定速動比率，確保比率大於一。另一個檢測財務健康的方法是債務股本比，用股東權益和資本盈餘的總合除以總負債，該數值應小於一，而且越小越好。
How to Avoid Value Traps in Stocks
"Value" investing is buying stocks that are perceived as being worth more than what you pay for them.[1] Stocks are valued most commonly by the net tangible assets of the companies they represent, earnings per share, and dividends they pay. Thus, a value investor would favor those stocks that have a low price/book ratio, low price/earnings ratio, and high dividend yield.
However, it could be dangerous to buy a stock that meets these criteria, because a stock that appears cheap may in fact be on the brink of bankruptcy and not a bargain at all, despite the figures. Sorting the true bargains from the false bargains (or "value traps") is not easy. Here are some things to look for that may help you see the distinction.
1
Stay clear of stocks that have dropped in price due to to exposed corporate fraud. Some recent examples like Enron, WorldCom, and Tyco experienced a marked drop in prices that made them look like bargains after their scandals were exposed. In the end, however, they found themselves on a relentless trajectory to zero, leaving shareholders with nothing. Wherever fraud is involved, the figures in financial statements that are used to determine value are meaningless, and the company simply cannot be valued appropriately. Moreover, once fraud is discovered, a company tends to have little or no value left that has not already been stolen by corrupt management. Do not consider stocks of companies involved in corporate fraud.
2
Beware of an overly optimistic outlook from a company's management. Any company that promises to deliver consistently increasing, double-digit earnings growth is unrealistic, and such promises, when they become undeliverable, may lead to fabrication of figures by management. Warren Buffett bought huge stakes in Freddie Mac during the 1980s when the stock was truly cheap. He liquidated his position for a $2.75 billion profit in the late 1990s after he saw signs that the overly optimistic goals of the company's management were unachievable.[2]
3
Avoid companies with high debt or leverage. Debt is a double-edged sword. In good times you can make a lot of money using leverage, and borrowing is easy. In bad times you can lose money very fast, and the time when you need money the most is when creditors start calling you and demanding repayment.
4
Avoid companies dealing in outdated products and services. Blockbuster is a good example: who needs to go to a physical store to get videos or DVDs when they can be downloaded at home with the click of a mouse? Likewise, newspapers and physical bookstore businesses have been hurt by the expanding Internet. Outdated products and services often signify that the lost revenues are probably lost forever and that a rebound in the stock price is unlikely.
5
Be careful of companies facing increasingly stiff competition. Look at the profit margins (net earnings divided by revenue) of a company through a period of five to ten years. Compare to profit margins of competitors in its industry. If the profit margins are decreasing through the years, that usually signifies that the company is unable to pass increasing costs on to its customers because of the need to maintain competitive prices. If a company is no longer competitive, it's better to avoid it despite the low valuations.
• For a good margin of safety to make sure a company is able to satisfy interest payments on its debt, look for companies with two-to-four times interest coverage (earnings before interest at least two-to-four times interest charges). Upper limit applies to industrial issues, especially cyclical ones; lower limit applies to more stable incomes such as utilities.
• A company with no debt is highly unlikely to go bankrupt, barring unforeseen misfortunes (such as a massive legal settlement against it) or an inability to sell its products for more than it costs to create those products (evidenced by negative net income on the income statement). On the other hand, excessive leverage can destroy even a great company.
6
Be wary of companies in highly regulated industries. Because of high fees and regulation costs in the U.S., for example, many companies have relocated their businesses to other countries like China. Most consumer goods are no longer made in the U.S. Payday loans are another example. Making $20 in fees for every $100 loaned out, payable in two or three weeks, is quite profitable. However, government caps that put the maximum interest rate at 36 percent per annum cut profits significantly.
7
Be careful when investing in stocks that have dropped due to a dividend cut, especially when the company does not expect to resume dividends any time soon. Dividend cuts usually mean the company has limited earnings to pay out. The price correction following a dividend cut can be prolonged. Don't buy until valuations are really compelling, as when significant price drops send the stock to 50 percent or less of its intrinsic value.
8
Watch out for missed earnings estimates. Analysts are generally quite lenient in their estimates and tend to revise their estimates downward before earnings are announced. This allows companies to beat their estimates and look good. Occasional missed earnings estimates with overreaction in the price is a solid reason to buy "on the dip," but a pattern of missed earnings estimates is foreboding.
9
Invest in profitable enterprises only. Look at the company's income statements dating back at least five years (ten is better). A consistently profitable company should have at least some earnings per share for each of the past five-to-ten years, preferably with an upward trend. A company with consistent negative earnings for several years may be too expensive at any price.
10
Look for insider buying. Insiders are in the best position to know how much their company is really worth. If the stock price is truly cheap, they will be buying the stock. There is only one reason why insiders buy: they expect the stock to go up. If you see a recent history of insider buying, it's a safe bet to follow suit. On the other hand, if you see many insiders selling a stock you're considering, it may be an ominous sign, and you should probably keep your hands off.
11
Check the balance sheet to make sure the company is healthy. One of the most important things to look for is that the company has current assets greater than current liabilities, to ensure that it can pay its bills in the short term. A more stringent test is to calculate the quick net asset value by subtracting inventory (which may be illiquid) and total current liabilities from current assets. Alternatively, determine the quick current ratio by dividing total current assets (less inventory) by total current liabilities. Make sure the ratio is greater than one. Another measurement of financial health is the debt-to-equity ratio, obtained by dividing total liabilities by the sum of shareholders' equity and capital surplus. The debt-to-equity ratio should be less than one; the lower, the better.
本文翻譯由兄弟財經提供
文章來源：http://www.wikihow.com/Avoid-Value-Traps-in-Stocks