Jagmeet Channa had worked at the bank for less than a year, but attempted to steal money by transferring $94.4 million and $47 million into two separate accounts.
Using the passwords of his banking collegues, Mr Channa wired the money into associates' accounts at Societe Generale in Casablanca, Morocco and Barclays in Manchester.
Charged with conspiracy to defraud and money laundering, 25-year-old Mr Channa's actions were described as "very serious" by the Judge Geoffrey Rivlin at Southwark Crown Court yesterday.
"This was no silly prank," he said. "This was a carefully planned and very serious attempt to transfer a fortune in money away and it almost succeeded."
Mr Channa was caught after the debt in each of the raided account was discovered by HSBC employees in Malaysia.