After almost a week of deliberations, a jury found Shkreli guilty of three of eight counts of securities and wire fraud.
Shkreli was accused of repeatedly lying to investors and then scheming to pay them back using fake agreements for things like consulting services.
A center of [attorney Benjamin] Brafman's defense was that Mr. Shkreli didn't intend to commit fraud, and he said in his closing argument that "good faith can, in this case, be a complete defense to every one of the charges".
Shkreli, who was acquitted of five of the eight charges against him in U.S. District Court in Brooklyn, characterized the verdict as a victory and called the case a "witch hunt".
"I don't think it mattered to him - it was just what he thought he could get away with", said Richard Kocher, a New Jersey construction company owner who invested $200,000 with Shkreli in 2012.
Prosecutors said that when Shkreli gave investors false assurances of financial security when accepted millions of their dollars and for investment in MSMB Capital and MSMB Healthcare.
Shkreli himself scoffed at prosecutors online, calling them "junior varsity" and referring to his trial as "a silly witch hunt perpetrated by self-serving prosecutors".
Christopher LaVigne, a former federal prosecutor who is now a defense lawyer at the law firm of Shearman & Sterling, said it was notable that prosecutors secured a conviction even though investors did not lose money, and said it could encourage more such cases in the future.
"In terms of people skills?"
Throughout the trial, Brafman portrayed his client as a troubled genius, never hesitating to point out Shrkeli's socially awkward behavior - several times reiterating one witness' comparison to Dustin Hoffman's performance as an autistic savant in "Rain Man" - but maintained that Shkreli "was always truthful to the mission".
Shkreli emphasized the jury's finding that he did not conspire to steal from Retrophin.
He faces as much as 20 years in prison.
He is now free on bail.