J
Simulated · primary-source grounded
Committee · Quantitative value

Joel Greenblatt

Good companies at bargain prices, found by formula.
Grounded in three books on value and special-situation investing
50%
Gross annualized at Gotham Capital, 1985-1994
2 variables
Return on capital and earnings yield, the entire Magic Formula
30.8%
Magic Formula back-test, 1988-2004, vs the S&P's 12.4%
Columbia
Adjunct professor of value investing since 1996
The philosophy

Buy good businesses, but only when they're cheap.

The simulated Greenblatt reasons from a disarmingly simple value framework that he spent a career proving works. His "Magic Formula" ranks companies on two variables and only two: return on capital, which identifies good businesses, and earnings yield, which identifies cheap ones. From that overlap he builds a diversified basket and holds it with patience.

"Choosing individual stocks without any idea of what you're looking for is like running through a dynamite factory with a burning match."

Before the formula, he made his name in special situations: spinoffs, restructurings, and merger arbitrage, the overlooked corners of the market where mispricings hide and most investors rarely look. The common thread is discipline: a repeatable, unemotional process applied consistently, especially through the stretches when it temporarily stops working. He insists the hard part isn't the strategy; it's sticking to it.

How the simulation reasons

The quantitative discipline, in his own framing.

Within the committee, the Greenblatt agent draws on his three books. When a company is evaluated, the system retrieves the passages most relevant to it, his reasoning on return on capital and earnings yield, on why a quantitative screen beats gut feel, on the patience the approach demands.

The voice that emerges is the committee's quantitative value check: focused on the numbers that signal a good business bought cheaply, skeptical of stories that aren't backed by returns on capital, and consistent in applying the same test to every name.

Primary sources

What this voice is built from.

You Can Be a Stock Market Genius
New York: Simon & Schuster, 1997
Primary · book
The Little Book That Beats the Market
Hoboken, NJ: John Wiley & Sons, 2005
Primary · book
The Little Book That Still Beats the Market
Hoboken, NJ: John Wiley & Sons, 2010
Primary · book

Sources are cited as the documented basis for this simulated investor. Furton Research does not reproduce or redistribute their text.

Role on the committee

The quantitative value check.

Greenblatt brings a numbers-first discipline that complements Buffett's qualitative judgment. Where Buffett weighs the durability of a moat, Greenblatt asks whether the returns on capital and the earnings yield actually clear the bar. He is the member most likely to anchor the committee to a measurable definition of cheapness, and a useful counterweight to verdicts driven by narrative rather than fundamentals.

The rest of the committee