Yet, despite his best efforts and $50 million in Pershing Square Capital's money to support his crusade, Herbalife's shares are up nearly 54% since before the start of his campaign in December 2012.
On Tuesday, Ackman gave what he called the "most important presentation" of his career in which once again described Herbalife, which markets vitamins and nutritional supplements, as a "criminal enterprise." If anything, his death-blow missed by a mile. Investors, who were bracing for a bombshell, shrugged off the less-than-solid evidence and sent the company's shares up 25%.
The activist investor is losing time to make good on his $1 billion short position.
Herbalife hasn't ruled out the option of suing Ackman over false claims, Herbalife's chief financial officer John Desimone told Bloomberg television Tuesday.
"That's on the table, that's an option. I think our case gets stronger every day," he said. "The rules of transparency that we operate under is not the same set of rules that Bill Ackman operates under."
Ackman's response: "Bring it on."
"From my perspective, Ackman has been daring Herbalife to sue him for some time," said John Coffee, a securities law professor at Columbia University.
A lawsuit would give the activist investor access to Herbalife's non-public records, which otherwise wouldn't be available to him. In civil litigations cases, like this would be, the defendant gets the first right to discovery.
"Ackman would want to see every email among Herbalife's executives mentioning his name or the word 'pyramid,'" said Coffee. "Remember, he has spent $50 million on his factual investigation of Herbalife so far, and civil discovery would get him more at a cheaper price."
Herbalife executives are well aware of the access Ackman could gain with any lawsuit, which may be why they have stayed away from any litigation so far.
In order for Ackman to be charged with any form of stock manipulation, Herbalife would need to prove that he knowingly spread misleading or false information about the company, according the U.S. Securities and Exchange rules. Otherwise, his criticisms fall safely within the bounds of First Amendment protections.
A court case, at the end of the day, may be exactly what Ackman's been waiting for.