Cole Anthony -- last years 15th overall pick -- is confessing his biggest rookie year screw up ... laying down wayyy too much cash on a chain prior to draft night.
TMZ Sports ran into the Orlando Magic star only hours before the 2021 NBA Draft ... and we asked the 2nd year hooper out of UNC how he treated himself after being picked in last year's 1st round.
"Before the draft, I bought myself a chain which I immediately regretted," the 21-year-old said. "It was a lot of the money at the time .