Marathon Digital Holdings (NASDAQ:MARA) continued their descent on Wednesday. As of 3:15 p.m. EST, Riot Blockchain stock was down 12% and Marathon Digital stock was down 13%. Popular cryptocurrency Bitcoin (CRYPTO:BTC) is down roughly 5% over the last 24 hours, which is likely playing a roll in the pair's decline. So what Both Riot Blockchain and Marathon Digital mine Bitcoin -- they provide computing power to help process transactions on the Bitcoin blockchain network, unlocking new Bitcoins as compensation in the process. As of the end of April, Riot Blockchain had mined 697 Bitcoins so far in 2021. For its part, Marathon Digital had mined 386 Bitcoins this year, as of May 6.