And despite taking a pass on telling jurors his story, the often-chatty Shkreli then accused prosecutors on Facebook of cherry picking evidence to show jurors, instead of offering them the "whole" story.
Shkreli for weeks had weighed his chance to take the witness stand in Brooklyn, New York, federal court, where he is accused of defrauding hedge fund investors and the drug company he founded, Retrophin.
Shortly afterward on Monday, Shkreli went on Facebook, and wrote the following post: "plead the fif when it comes to the fam im like a dog i dont speak but i understand."
The line that Shkreli wrote is actually a sentence that begins "Plead the Fifth," and is from the Jay-Z song "Never Change."
Shkreli didn't quote other lyrics from that song, whose chorus includes the lines: "I'm still f---n with crime cause crime pays. Out hustlin, same clothes for days. I never change, I'm too stuck in my ways, I never change the line."
Shkreli has a history with Jay-Z.
Prosecutors have said that Shkreli's "ways" over the years, like the ones in the "Never Change" lyrics remained remarkably consistent: telling investors that he had considerable success playing the stock market, while in reality he was routinely losing their money.
An indictment alleges that Shkreli defrauded a group of investors at two hedge funds he ran, MSMB Capital and MSMB Healthcare, by misleading them about the funds' financial performance.
FBI Special Agent Michael Braconi testified Tuesday that on Sept. 4, 2012, when Shkreli signed an agreement to pay Merrill Lynch $1.3 million against more than $7 million in losses MSMB Capital incurred in a short-sale transaction, that agreement noted that MSMB Capital had "$0" in cash or equivalents as of the September date.
Despite that, Shkreli told investors over the next two weeks that they had plenty of money, and offered to redeem that cash to them if they chose, since he was shuttering the fund.
The indictment also charges that instead of paying them cash as promised, Shkreli gave them combinations of stock and cash that he had looted from Retrophin.
That was despite the fact that the investors had, for months, asked for the money to be redeemed in cash from the MSMB funds.
Shkreli denies the charges.
In testimony Tuesday, Braconi said that there are no records that MSMB Capital ever invested any of its funds in Retrophin.
Braconi's testimony raises the question of why investors in MSMB Capital were paid back by Retrophin with stock or cash if their money never was invested in the drug company.
The agent also said that records show that MSMB Healthcare invested slightly more than $2.1 million of its funds into Retrophin.
But that amount is less than half of the $4.33 million that Shkreli was claiming to investors that they had in MSMB Healthcare, Braconi said.
And when Shkreli was giving those investors financial statements detailing the purported $4.33 million in assets, MSMB Healthcare actually had just $112,000 or so in the bank, the agent said.
Shkreli on Monday offered his Facebook followers a bit of math of his own, although without any actual numbers.
"Who likes math? Time for a math lesson. The whole is equal to the sum of its parts. Not the parts you cherry pick," Shkreli wrote.
"You can't omit important pieces of a story and expect the people will be too stupid to figure it out."