Bitcoin’s three-year rally may be over, with signs pointing to the leading cryptocurrency entering a prolonged bear market. That’s according to blockchain data firm CryptoQuant, whose researchers said in a Friday report that investors should be prepared for the end of Bitcoin’s four-year cycle. Buyer exhaustion means the biggest digital coin could still drop as low as $56,000, the report noted. But it reassured investors that such a move was unlikely — if Bitcoin does drop that low, it would be the sharp ...