Sergey Aleynikov has been released on bail after being arrested at Newark airport in New York on suspicion of improperly copying trading system code and uploading it to a file-sharing service.
The 39-year-old was granted bail on the condition that $750,000 was paid as a personal recognizance bond.
He is alleged to have stolen code that can be used to trade commodities and stocks at a high speed by quickly analyzing information from global markets.
Mr Aleynikov left Goldman Sachs -where he earned a $400,000 salary - in June of this year to work for a Chicago-based firm.
In related news, US federal prosecutors announced earlier this month that they are to charge at least ten other people in relation to the $65 billion Bernard Madoff scandal.
Madoff was sentenced to 150 years in prison for his role in the crime.