Why Wall Street Is Ignoring “CAPE” Fear

When stocks rocket to new records daily, it’s incredibly tempting to dismiss “CAPE Fear.” And the pros on Wall Street are unleashing every new age theory than can conjure to undermine its validity. The naysayers are wrong. Here’s why the CAPE--cyclically-adjusted price-to-earnings ratio--should indeed instill if not terror the deepest skepticism.

For decades, top value investors and market brainiacs have embraced the highly-regarded CAPE index as one of the most reliable yardsticks for weighing under versus overvalued markets. CAPE fans include Rob Arnott of Research Affiliates, Jeffrey Gundlach of DoubleLine, and John Hussman of Hussman Funds.

But now, the bull market’s precedent shattering power and momentum has shaken the faith of one of its staunch supporters, the bubble-unmasking dean of deep value investing, Jeremy Grantham of GMO.

In letters to investors in mid-2017, Grantham stated that “this time, things seem very, very different,” arguing that the extremely high CAPE ratio wasn’t just a flagrant sign of prices gone wild, its signal in the past, but a reflection of sustained, unusually high rates of earnings growth driven by “increased monopoly, political, and brand power.”

But Vitali Kalesnik of Research Affiliates, a firm the oversees investment strategies for $300 billion in mutual funds and ETFs, rejects Grantham’s view that high valuations are here to stay, along with the growing perception that the CAPE is busted. “Grantham’s argument that monopolistic and brand power made companies extremely profitable is a good description of the past,” Kalesnik told Fortune. “But projecting the theory into the future is very dangerous. The CAPE isn’t projecting high earning growth from here, it’s projecting what it always projects from these levels, low returns in the future.”

Along with Research Affiliates’ colleagues Arnott and Jim Masturzo, Kalesnik presents the pro-CAPE manifesto in an article entitled “CAPE Fear: Why the Cape Naysayers are Wrong.” Before examining his arguments, it’s important to understand the CAPE methodology. Developed by Yale economist Robert Shiller, it uses not current earnings-per-share as the denominator, but a ten-year average of inflation-adjusted EPS. Smoothing earnings eliminates spikes and valleys that can temporarily make PEs look artificially cheap (spikes or unsustainable runs) or too pricey (the financial crisis collapse).

As its most ardent advocates have long acknowledged, the CAPE’s role isn’t calling turning points in the market. On the contrary, it’s a tool designed to forecast future returns–what returns are likely to follow over, say, the next ten years, depending on the starting CAPE. Put simply, when the starting CAPE is extremely low, future returns can surge into the double-digits. And when today’s CAPE is highly elevated, gains over the next decade tend to be piddling, a pattern that repeats itself with remarkable consistency.