Bill Ackman

Founder and CEO of Pershing Square Capital Management, the hedge fund he started in 2004 after an earlier fund, Gotham Partners, which he launched at 26. An activist value investor — he takes large, concentrated stakes in a handful of companies and works to change how they are run — Ackman has been at the centre of some of the most public trades of the past quarter-century: the General Growth Properties bankruptcy bet, the Canadian Pacific proxy fight, the Allergan/Valeant battle, the MBIA and Herbalife shorts, and the 2020 COVID credit hedge.

Pershing Square runs a deliberately tiny operation — around 40 people, owning only seven or eight businesses at a time — which Ackman likens to the Navy SEALs rather than the Army. He learned the craft from Benjamin Graham’s The Intelligent Investor and from Warren Buffett, whose record he openly aims to match. He holds bachelor’s and MBA degrees from Harvard, and in recent years has become a prominent and combative public voice on X (formerly Twitter), on university governance, free speech, and the press.

Core positions

Ackman is a concentrated value investor. He buys a few businesses he can predict with high confidence for a decade or more, at a price well below his estimate of intrinsic worth — Graham’s margin of safety — and treats not losing money as the foundation of long-run returns. He prizes durable, hard-to-disrupt businesses with wide moats, and judges management by incentives, track record, and whether they run the company for the business or for themselves.

As an activist, he holds that an engaged owner with the right ideas — not merely a large stake — restores the balance of power between shareholders and management, a corrective to the passivity of index funds that now dominate the market. On risk, he is severe: short selling is treacherous because losses are unbounded, so Pershing Square shorted only two companies and no longer shorts; and one should never borrow against one’s securities, lest a market panic force a sale at the bottom. His worst losses (Valeant above all) he attributes to breaking his own principles, and his recovery to refocusing on fundamentals and compounding small daily progress.

A recurring thread across his investing and his public fights is governance: businesses and institutions alike fail, in his view, because of governance failures, and incentives drive all behaviour.

In the wiki

• Bill Ackman on Activist Investing, Concentrated Bets, and Financial Battles — value investing and margin of safety, concentrated portfolios, activist campaigns (Wendy’s, General Growth, Canadian Pacific), short selling and the Herbalife war, the Valeant loss and recovery, Harvard and the press