眼下，股市記錄似乎每天都在刷新，但華爾街卻向投資者發出的信息卻是背道而馳。這些啦啦隊長們稱，從某些方面來看，股票實際上并不貴。但是，我們一定得小心那些利用遠期盈利預測的投機商。

對于那些仍鼓勵購買股票的市場策略師和專家來說，要證明眼下高高在上、甚至貌似過高的估值實際上并沒有那么高，并非是件易事。遠期市盈率也就應運而生。這一大受歡迎的指標的計算方法是：用未來4個季度預測的標普500的每股收益平均預估值，除以標普當前的價格。這些未來收益預估過于樂觀，幾乎不約而同地預測了利潤的大幅提升。但綜合來看，這一方法所得出的“遠期”價格/收益市盈率（P/E）實際上總是比按照實際賬面結果（也就是過去4個季度的實際營收）計算的市盈率低得多。

在12月27日接受CNBC采訪時，瑞士信貸首席市場策略師喬納森·格勒布曾預測，標普500將在2018年底達到3000點大關（較采訪之日的價格將上漲12.2%），而他的依據便是遠期市盈率。格勒布說：“讓我們按照大多數投資者的方式，從遠期的角度來看待市盈率。在稅改法案出臺之前，股票的市盈率是18.25。也就是說，公司每掙1美元，人們就會自愿掏18美元或更多的資金來購買該公司的股票。如果收益的增幅與我的預期一致，那么市盈率倍數就會降低，因此我覺得人們的購買價格其實相當于17倍的遠期盈利。”

在大多數投資者看來，市盈率前景低于20會讓他們感到欣慰不已。但是這一看似合理的遠期數字頗具誤導性。為了弄明白其中緣由，不妨看看以下兩個因素。首先，讓我們把如今的遠期市盈率與它的同類——長期遠期市盈率進行對比，而不是與過去的市盈率對比。此外，我們還需發問：哪種類型的收益預測必須低于20倍市盈率，這種預測合理嗎？

價格創歷史新高——過去或者遠期

我們有必要強調，按照過去4個季度的GAAP（美國公認會計準則）收益計算，當前的股票市盈率達到了驚人的24，較1990年以來的平均值19高出了26%，比1888年以來的平均值16.7高出了44%。耶魯大學經濟學家羅伯特·席勒開發的CAPE市盈率更是達到了令人生畏的33.3，僅次于21世紀初的科技泡沫期間的股市估值。

在CNBC采訪中，格勒布似乎根據運營收益來計算遠期市盈率。然而，使用GAAP收益計算的遠期預估值，雖然略低，但也采用了類似的方法。這又讓我們回到了第一個問題：如果對比當今的遠期估值與過去的預測，結果會如何？按照歷史標準來看，遠期市盈率是低了還是高了？

標普Global Market Intelligence稱，分析師根據GAAP利潤計算的四個季度（以1月8日周一為截點）遠期市盈率平均預估值為19.25。從這一數字來看，股票的價格是十分合理的，不是嗎？并不一定。自2003年初以來，每年1月8日的平均遠期預測為15.7。因此當前19.25的估值高于16年以來的平均值。即便我們將2000-2002年（當時科技股的狂熱仍在推動預測不斷膨脹）的超高預測值計算在內，這一數字仍將高出平均值13%。

第二，回答以下問題會讓我們得到啟發：為了讓遠期市盈率低于20，那么利潤預計應上漲多少？以2016年第三季度（標普500依據報告的營收的最后整個季度）為截點，過去12個月的GAAP每股收益總計達到了107.08美元。以2018年第四季度末為截點，分析師預測前四個季度每股盈利總計將達到136.75。漲幅接近28%。

別忘了，這一驚艷的業績也只會將遠期市盈率倍數降至19.25，仍然遠高于該數據的平均值。這也無法讓股票成為香餑餑。這種情況會發生嗎？不大可能。截至第三季度，標普500的運營利潤率為10.7%，創7年以來的新高，是標普歷史上最輝煌的數字之一。即便美國去年年底已然通過了大幅減稅法案，但28%的運營利潤率增幅卻需要空前絕后的業績作為支撐。

為了判斷股票價格是否過高還是處于合理區間，我們應該去看看股市的支撐點，例如過去的業績，GAAP數據，或Shiller市盈率或CAPE這類更好的參考標準。追隨遠期市盈率無異于夢游幻境。（財富中文網）

譯者：馮豐

審稿：夏林

At a time when the stock market seems to set new records every day, Wall Street is sending a counterintuitive message to investors: By some measures, the cheerleaders say, stocks are actually cheap. But beware of bulls bearing forward earnings projections.

For market strategists and pundits arguing that stocks are still a buy, it’s a major challenge to prove that today’s lofty, even seemingly excessive, valuations aren’t really so lofty. That’s where forward earnings come in. This much-favored metric involves taking analysts’ consensus estimates for the S&P 500’s earnings-per-share, as predicted for the next four quarters, and dividing that number by the S&P’s current price. Those future-earnings estimates skew bluebird optimistic, almost invariably pointing to big increases in profits. Put it all together, and that methodology establishes a “forward” price-to-earnings multiple (P/E) that’s virtually always far lower, and a lot more fetching, than the P/E based on results already on the books—in other words, the actual earnings recorded over the past four quarters.

In an interview with CNBC on Dec. 27, Jonathan Golub, chief market strategist for Credit Suisse, cited the forward P/E to justify his prediction that the S&P 500 would reach 3000 by the close of 2018 (a 12.2% increase from where prices stood that day). “Let’s look at multiples the way most investors do on a forward basis,” declared Golub. “We were looking before the tax plan at an 18-and-a-quarter multiple for stocks. For every dollar you earn you’re willing to pay 18 or more dollars to buy that company. If earnings go up as much as I expect, the multiple gets cheaper, so I think that you’re probably on the actual earnings paying something like 17 forward.”

To the ears of most investors, the prospect of P/Es well below 20 are comforting. But the reasonable-sounding forward numbers are highly misleading. To understand why, let’s examine two factors. First, let’s look at how today’s forward P/E compares not with trailing P/Es, but with its own species, forward P/Es over long periods. And second, we should ask: What kind of earnings projections are required to arrive at a sub-20 P/E, and are they reasonable?

Historically high prices—backward or forward

It’s important to emphasize that the current stock multiple, based on trailing, four-quarter GAAP earnings, is a daunting 24. That’s 26% higher than the average of 19 since 1990, and 44% above the figure of 16.7 since 1888. The CAPE P/E developed by Yale economist Robert Shiller is even more forbidding at 33.3, a number surpassed only by valuations during the tech bubble of the early 2000s.

In the CNBC interview, Golub appears to be referring to forward P/Es based on operating earnings. But the forward estimates using GAAP earnings, though slightly lower, follow a similar pattern. Which brings us to the first point: How do today’s forward estimates compare with past projections? Is the forward P/E low or high by historical standards?

According to S&P Global Market Intelligence, the analysts’ consensus estimate of four-quarter forward P/E based on GAAP profits stood at 19.25 as of Monday, Jan. 8. Makes stocks sound reasonably priced, right? Not necessarily. Since early 2003, the average forward forecast for Jan. 8 of each year was 15.7. So the current estimate of 19.25 is 22% higher than the sixteen-year average. Even if we include the gigantic forecasts from 2000 to 2002, when the tech craze was still inflating projections, the current number is 13% above average.

Second, it’s instructive to answer this question: Just how much are profits expected to surge in order to push the forward P/E below 20? As of Q3 2016, the last full quarter of reported earnings for the S&P 500, GAAP trailing 12-month earnings per share (EPS), in the aggregate, totaled $107.08. By the end of Q4 2018, analysts predict total, four-quarter trailing EPS of $136.75. That would be a rise of almost 28%.

And remember, that epic result would only lower the forward P/E to 19.25, still much higher than the average for that figure. That hardly tags stocks as a bargain. Will it happen? Unlikely. As of Q3, S&P 500 operating margins stood at 10.7%, the highest level of seven years, and one of the most elevated figures in S&P history. Even in the wake of the huge tax cut passed late last year, boosting that operating-margin figure by 28% would require almost unprecedented performance.

To judge whether stocks are extremely expensive or reasonably valued, trust the stalwarts, like the trailing, GAAP numbers, or even better, the Shiller P/E or CAPE. Following forward multiples is a trip to fantasyland.