So which of the enumerated types of securities listed in 15 U.S.C. §77b(a)(1) does a cryptocurrency fall under? Also, how often has SEC gone after the purchase

So which of the enumerated types of securities listed in 15 U.S.C. §77b(a)(1) does a cryptocurrency fall under? Also, how often has SEC gone after the purchaser of an unregistered/unexempted security. Not very often, I would guess.