Riot Platforms said Friday it expanded its Bitcoin holdings, days after MicroStrategy snapped up more of the world’s largest token. Riot said it acquired 5,117 Bitcoin for roughly $510 million between Dec. 10 and Dec. 12, representing an average price of $99,669 per Bitcoin. This brings Riot’s total holdings to 16,728 units of digital currency, as disclosed in the company’s latest 8-K filing with the Securities and Exchange Commission.