The three major U.S. stock indexes opened mixed, with the Dow down 0.24%, the S & P 500 up 0.23%, and the Nasdaq up 0.29%. Cryptocurrency concept stocks opened down, with MicroStrategy (MSTR. O) down 5.9%, Coinbase (COIN. O) down 3.9%, and Riot Blockchain (RIOT. O) down 5.1%.