1 Iki Piki: Why would Chekov want to mine Bitcoins? The Federation has a post-scarcity economy. They don't use money.
2 Serron: That's the brilliant part! Bitcoins are artificially scarce. So they have value.
3 Iki Piki: But nothing else is scarce, so there's nothing worth trading them for.
4 Serron: Right! So it's easier to hoard them and die rich! Then you win!!

Serron is nothing if not consistent.

Money in Star Trek seems to be one of those (many) schizophrenic things that changes at the whim of the writers. In the Original Series, they were quite adamant that the Federation doesn't use money. Except for those times when Cyrano Jones was selling tribbles for ten credits apiece, or when Harry Mudd was selling love potion crystals for 300 credits. Then in Deep Space Nine, Quark ran a currency-based business, and members of the crew often gambled using suspiciously money-like bets. You'd be forgiven for thinking that they'd pretty much abandoned the experiment of a moneyless society and just gone back to having some convenient unit of exchange.

Picard was perhaps the most strict about pointing out that the Federation didn't use money any more. Only to be foiled when he meets long-time friend Captain Phillipa Louvais in the episode "The Measure of A Man", and she says, "Picard, call me. You can buy me dinner. " (This is also the episode that introduces Data to the game of poker, in which the players are betting.... what?)