Check out the companies making headlines before the bell. Crypto stocks â Stocks tied to the price of bitcoin gained as the cryptocurrency inched higher on Tuesday. Bitcoin proxy MicroStrategy advanced nearly 5%, while crypto services provider Coinbase rose more than 2%. Miners Mara Holdings and Riot Platforms also each moved more than 2% higher. VeriSign â The internet stock jumped more than 3% in premarket trading after a regulatory filing revealed that Warren Buffett’s Berkshire Hathaway bought more shares in the company. The conglomerate added 76,487 more shares of Verisign over the past three trading days for 15.6 million. The firm also purchased the stock in the prior week. Sangamo Therapeutics â Shares of Sangamo Therapeutics plunged more than 54% after the company said its partner Pfizer ended their hemophilia A gene therapy co-development agreement , delaying the prospects of bringing the development to market. Sangamo now has the rights to the product and said it will explore options to advance it. Pfizer shares were 0.3% higher, meanwhile. EQT â The energy company gained less than 1% a day after announcing the closing of a midstream joint venture with Blackstone Credit & Insurance . EQT received $3.5 billion net from Blackstone for a non-controlling common equity interest in the new venture, which the energy company used to pay down some of its outstanding debt. The stock has been on a tear this quarter, up more than 27% as natural gas prices surge. Tesla â The electric vehicle stock popped 1.7%, reigniting an end-of-year rally after posting three straight losing sessions. Despite the recent pullback, Tesla shares have surged nearly 21% in December, bringing the megacap tech stock’s annual gain to around 68%. Super Micro Computer â Shares gained more than 1% after closing the previous session as the worst performer in the S & P 500, falling around 4%. While the stock has still increased about 8% this year, it has slumped into year-end, shedding 6% month to date. Nvidia â The chipmaker gained almost 1%, adding to the gains seen in the previous session. On Monday, Nvidia was the sole stock in the Dow Jones Industrial Average to finish in the green, rising about 0.4%. â CNBC’s Alex Harring, Yun Li, Pia Singh and Lisa Kailai Han contributed reporting.