After Ackman sold his shares at a substantial profit after a dispute over executive succession, the stock price collapsed, raising criticism that the sale of Wendy's fastest growing unit left the company in a weaker market position.

[12] On January 9, 2009, the fund disclosed a 7.4% ownership stake in General Growth Properties (GGP) according to documents filed with the SEC,[13] becoming the second-largest shareholder behind Brookfield Asset Management.

[18] In July 2012, Ackman acknowledged to CNBC he had acquired shares in Procter & Gamble worth approximately $1.8 billion, a 1% stake in the company, with the idea of taking an activist role within the corporation.

[23] In 2013, Pershing Square acquired a $2.2 billion stake in Air Products & Chemicals,[24] and nominated Matt Paull to serve on the company's board.

Ackman, who joined Valeant's board in March 2016, commented on the company's 88% loss since August 2015 stating, “This is going to be a badly scraped knee that may even require stitches but it is not life threatening... We should be able to recover the lion's share of our investment—if not all of it—over time".

[32] In 2018, Ackman dumped $500 million into the publicly traded arm of Pershing Square Capital Management stating it was significantly undervalued at roughly $15 a share.

[39] He closed the position less than three months later citing geopolitical risks surrounding the Israel-Hamas war and slowing economy, netting $200 million in the process.

[40][41] Pershing Square Tontine Holdings was a blank check company formed by Bill Ackman that went public on July 22, 2020, at a value of $4 billion and traded under the ticker symbol PSTH.U before the split of its warrants and shares.

[44] In July 2022, Ackman addressed PSTH shareholders saying that he would return the funds of the SPAC as he was "unable to consummate a transaction that both meets our investment criteria and is executable.

[50] In December 2012, Ackman announced the firm had made a $1 billion short bet against Herbalife, a maker of weight-loss and vitamin supplements, calling the company a "pyramid scheme".

[52] After a persistent political and grassroots campaign funded by Ackman and the firm,[53][54] the Federal Trade Commission initiated a civil investigation into Herbalife, causing its stock to drop enough that by March 2014, Pershing Square was nearly even on their bet.

[58][59] In July 2016, Herbalife settled with the Federal Trade Commission, agreeing to pay $200 million and restructure its business practices in exchange for not being labelled a pyramid scheme.

[60][61] In June 2014, Pershing Square was the largest institutional holder of the shares of Platform Specialty Products Corporation (NYSE: PAH), owning a 24.28% stake.