He has actually lost over $20 million. The $17 million figure was just for the period after he rejoined Full Tilt post black friday. I just wrote a piece today actually (live on saturday) about how an entire high stakes economy can be propped up by one person like Gus, or Guy, or Andy Beal etc. He hasnt played for a month and the nosebleed games have died.
These losses are since about 2007, so before that, who knows?
FYI from every nosebleed player I have asked, the site that records these results (HighstakesDB) is about 95% accurate. I'm pretty certain if Gus had not lost that much, he or FTP would have made a point of saying so.
Fun pop fact though, he is actually the biggest recorded winner in online stud games.
As a shareholder for FTP of old, I'm sure he had a bit of a buffer for those 20 million wins.
It would seem logical to assume he was winning pre 2007.