Justin Bieber made somewhere between $500 million and $1 billion as the world’s biggest pop star, but he blew it all … and ended up being in such dire financial shape he had to sell his music catalog for $200 million.

TMZ has a new documentary, “TMZ Investigates: What Happened to Justin Bieber,” now available on Hulu, and part of our investigation digs into Justin’s money problems.

People on Justin’s side told us he was on the verge of “financial collapse” back in 2022 … so much so that he felt he had to sell the rights to his music that December.

We’re told Justin’s manager Scooter Braun tried to tell him it was a bad idea to sell so early in his career, and to at least wait until January 2023 to get a tax break … but Justin didn’t want to wait so he sold it in December.

Lots of artists have sold their catalogs, but Justin is by far the youngest to do it … and we’re told being broke had a lot to do with his decision.

Our Bieber documentary also explores Justin’s mental health, marriage, money troubles, his church and his career.