Fuck Up Some Commas is a term which was made popular by Hip Hop artist Future in his song "Fuck Up Some Commas." Comma is slang for money. Fuck Up Some Commas means to spend money.
If someone's out balling/spending money they might tell someone that they're in the process of fucking up some commas. If you're making it rain at a strip club, you're fucking up commas.
In Future's "Fuck Up Some Commas" song, he raps, "Hundred thou, another hunnid thou - Three hundred thou to five hundred thousand - A million, let's have a money shower Let's fuck up some commas."