MicroStrategy CEO Michael SaylorJoe Raedle/Getty ImagesThe lack of a spot bitcoin ETF means some investors are looking for other ways to gain exposure to cryptocurrencies.Investors can buy stocks that have exposure to the crypto sector via mining and direct holdings.These are the 9 stocks with the highest correlation to bitcoin and ether, according to JPMorgan.Other than buying it directly, US-based investors have few options to gain exposure to cryptocurrency tokens like bitcoin and ether.While multiple futures-based bitcoin ETFs launched over the past two months, they come with high tradings costs that could deviate from the underlying return of bitcoin.