Looking to bring cryptocurrencies to mainstream finance, Fidelity Investments is hoping to launch its own Bitcoin (BTC-USD) exchange-traded fund called the Wise Origin Bitcoin Trust.If approved by the SEC, the ETF will track the performance of Bitcoin as measured by the movement of the Fidelity Bitcoin Index, a spot price barometer the investment giant takes from various Bitcoin markets and exchanges.To date, the SEC has repeatedly rejected applications for Bitcoin ETFs, arguing that the market was not ready yet despite a growing number of applications. Last week, the agency acknowledged a Bitcoin ETF proposal from VanEck.