A jury Tuesday began deliberating the fate of a Yale University-educated investment banker who insists he never told his father to trade securities based on the insider information he shared casually with his wife and parents.

Prosecutors claim Sean Stewart conspired with his father and a broker the son never met to make trades ahead of five company mergers, producing over $1 million in illegal profits.

Stewart, 35, testified that he never imagined his father would make trades based on his mention of company names as he talked about deals he was working on while working at JPMorgan Chase & Co. and Perella Weinberg Partners LP. His father pleaded guilty in the case and was sentenced to a year of home detention.

Shortly after beginning deliberations after noon, the Manhattan federal court jury asked for a definition of insider trading. It deliberated for nearly six hours before going home for the day. Before leaving, jurors asked to receive a copy Wednesday of all of Stewart's testimony as well as the testimony of one of the government's chief witnesses, the broker who carried out the illegal trades.

In the morning, Assistant U.S. Attorney Brooke Cucinella pointed at Stewart as she said in a rebuttal summation that the defendant was the "one person who everybody agrees is a liar."

"The evidence should leave you no doubt that when it serves his purpose, he lies," she said.

Cucinella directed jurors to look at "blatant inconsistencies" in Stewart's testimony before deciding to convict him of insider trading charges.

On Monday, defense lawyer Martin Cohen blamed Stewart's father, Robert Stewart.

"What he did is so horrible it's hard to understand," Cohen said.

Stewart had testified that his father's bad acts "resulted in the loss of my career and reputation."