Mr Trump was found liable for committing fraud in New York in a summary judgment in the case last month. The trial – including Cohen's testimony – will determine the extent of any penalties levied against Mr Trump.
In 2018 Cohen pleaded guilty to charges of tax evasion, making false statements to a federally insured bank, and campaign finance violations. He admitted to paying two women – including Stormy Daniels – hush money to keep them from publicly discussing their affairs with Mr Trump and disrupting his 2016 presidential campaign.
He ultimately spent just over a year in prison and an additional year and a half of home confinement.
After his second day of testimony, Cohen and his attorney, Danya Perry, addressed the crowd outside the courthouse.
Cohen told the press that he and Mr Trump – who was in the courthouse – made direct eye contact “several times” during his testimony.
In his trial testimony, Cohen accused Mr Trump of acting like a “mob boss” by using intimidation to pressure his employees to fraudulently inflate his wealth and assets on his behalf without explicitly ordering them to do so.
Mr Trump stormed out of the courtroom after his lawyers failed to convince Judge Arthur Engoron to rule in Mr Trump’s favour after arguing that Cohen’s credibility issues damage the case. His abrupt departure drew gasps from the audience as he muttered on his way out.
Cohen also told the crowd outside the courthouse that Mr Trump looked "resigned" during the hearing.
"I saw a defeated man," Cohen said. "I saw somebody that knows that it's the end of the Trump Organization: Already found guilty of fraud, the license will ultimately be taken, and now this entire case is merely about how much. This is merely about how much disgorgement [New York Attorney General Letitia James] will be seeking."
Cohen said Mr Trump's dramatics were likely a reflection of the former president's frustration over having to face "accountability" for his actions.
"You may have seen Mr. Trump storm out," Cohen said. "He stormed out because they wanted to make a motion to dismiss the case. To which the judge responded, 'yea, absolutely not.' You know why? Because he will ultimately be held accountable. And as I said the other day, that's what this is all about. It's accountability."
Earlier on Wednesday, Mr Trump was fined $10,000 for violating the trial’s gag order a second time, after his comments outside of the courtroom appeared to target the judge’s chief clerk.
His attorneys have vowed to appeal the sanctions.