Forbes made it official Tuesday ... saying Ye had lost his billionaire status in the wake of Adidas ending their partnership with the guy. While Adidas on its own might not have technically torpedoed his billions -- they say it's a combination of several deals, including Gap, falling apart of late -- Forbes does note it was a HUGE part of his wealth, and the final nail in the coffin.

Now -- after all this fallout -- Forbes claims KW is worth somewhere in the ballpark of $400 million. This is a huge dip from where he was a couple years ago, when his net worth was valued at around $1.3 billion with a majority of his public assets in consideration.

The majority of Kanye's riches are now coming from a select few sources, Forbes says, including real estate, liquid cash, his music catalog and a less than 5% stake in Kim Kardashian's Skims brand.

Unclear how much of his money was wiped out by just Adidas, but ya gotta imagine it was a pretty penny's worth ... considering the company says they're losing nearly a quarter of a billion dollars in net profits by cutting him/his shoes off, just in this fourth quarter alone.