Both men are facing fraud charges related to accusations that they encouraged investment in their hedge funds in early 2007, despite being aware of the likelihood that a dire financial crisis that was about to hit the global economy.
When the funds collapsed in 2007, investors lost $1.4 billion.
Within a year, Bear Stearns itself became one of the biggest casualties of the financial crisis and was bought out by JPMorgan Chase.
In her closing argument, prosecutor Ilene Jaroslaw summed up her view of the case to the Brooklyn courtroom.
"The two defendants lied to their investors," she said.
"It's not about the future but a case of black and white lies."
But Mr Cioffi's lawyer, Dane Butswinkas, retorted that the prosecution had based their case around "misleading sound bites" taken from emails between the pair.
The two men could face 20 years in jail if convicted and the case continues.
By Gary Cooper