MicroStrategy, Riot Blockchain stocks tank after bitcoin drops below $34K

With bitcoin (BTC-USD) extending last week's declines and sinking below $34K to a six-month low, stocks closely linked with the world's largest cryptocurrency tumble in premarket trading. Bitcoin (BTC-USD) drops 6.6% over the past 24 hours to $33.8K. The largest crypto by market cap is increasingly correlating with moves in the U.S. stock market in recent weeks. The 40-day correlation coefficient for bitcoin and the Nasdaq 100 reached almost 0.66, Bloomberg reports, citing data it has compiled since 2010. And lately investors are reducing their risk, pulling down stocks and crypto. Other cryptocurrencies are sliding, as well. Ether (ETH-USD) -11% to $2.23K, Cardano (ADA-USD) -13%, Binance Coin (BNB-USD) -11%, Solana (SOL-USD) -11%, dogecoin (DOGE-USD) -7.6%, Shiba Inu (SHIB-USD) -14%. MicroStrategy (NASDAQ:MSTR), which holds 1,914 bitcoins as of Dec. 29, sinks 13% and bitcoin-miner Riot Blockchain (NASDAQ:RIOT) falls 9.9% before the market open. Looking at other bitcoin miners, Marathon Digital (NASDAQ:MARA) -11%, Bitfarms (NASDAQ:BITF) -13%, Hive Blockchain (NASDAQ:HIVE) -13%, Hut 8 Mining