Bitcoin (CRYPTO: BTC) mining giant Riot Platforms Inc. (NASDAQ:RIOT) has upped its stake in rival Bitfarms Ltd. (NASDAQ:BITF) to 14% by purchasing an additional $3.87 million worth of shares as part of its ongoing hostile takeover bid. What Happened: Riot Platforms procured another 1,432,063 shares of Bitfarms at approximately $2.70 per share, The Block reported Thursday. This latest acquisition brings Riot’s total ownership to 57.62 million shares, or about 14% of Bitfarms. Bitfarms had earlier this week implemented a “poison pill” strategy to prevent the takeover, a move that would dilute th…