Newly-retired Matt Barnes says the 'B' in his last name could stand for BILLIONAIRE in just a few years ... revealing his master money plan to join the 3 Commas club by the time he's 50.
Barnes was getting ready to attend an event for his new company, Active Dreamers -- which makes NBA pillows and blankets -- when he told us why he's dead serious about getting to that next level of wealth.
There's more ... Barnes says his portfolio is ready to explode -- he's even got a production company kicking out big projects, including a documentary called "Tale of Four Cities" due out in 2018.
We also asked if Barnes would ever return to the court with the BIG 3 ... and Ice Cube ain't gonna like his answer.