The former aides of Bernard "Bernie" Madoff, who was responsible for the largest Ponzi Scheme in history, were found guilty on all counts.
A New York court found that computer programmers, Jerome O'Hara and George Perez, back-office director Daniel Bonventre, and portfolio managers, Annette Bongiorno and Joann Crupi, were found guilty of securities fraud and conspiracy to defraud clients.
They will all be sentenced in July this year.
Madoff masterminded a Ponzi scheme worth $65bn (£40.1bn, €47.5bn) in 2008, but five years later the courts are still being kept busy by a raft of lawsuits.
In 2009, Madoff pleaded guilty and was sentenced to 150 years in prison for controlling the biggest Ponzi fraud yet detected.
His brother Peter Madoff also pleaded guilty in 2012 to his part in the fraud and was sentenced to 10 years in jail.
At the beginning of 2013, JPMorgan agreed to pay more than $2bn to settle claims related to Madoff's Ponzi scheme after US authorities said the Wall Street giant had "critical and widespread deficiencies" in its programmes to prevent money laundering and other suspicious activity.
JPM paid $1.7bn to settle criminal charges and a $350m civil penalty.