Pirate's real business is running the US petroleum refining industry. Because his pirates are holding back shipments of oil, supply is held artificially low and demand has maintained or increased. Pirate has a side venture that is run through GPUMAX that, instead of hashing bitcoin hashes, he has found a way to run oil exploration simulations in a distributed manner through bitcoin clients to search for undiscovered oil deposits in Texas. He then uses the remaining funds from his pirates' ransoms to purchase the mineral rights to the oil deposits that he has discovered. Pirate then extracts this oil, refines it at his refineries and, due to having a cheap source of oil, he is able to undercut his competitors for massive profits. Pirate then returns part of the profits to depositors of First Pirate Savings and Trust so as to keep anyone from asking questions.
In the end, Pirate is a high seas pirate and an oil baron/pirate. Don't ask too many questions or his new venture in "protection" services might add you to the list.