Bitcoin rallied to a four-week high approaching $45,000 on Thursday amid record highs in U.S. equity indexes. Bitcoin, which fell as low as $42,700 on Wednesday, climbed almost 5% to $44,800, the highest since Jan. 11, according to CoinDesk data. “Technically speaking, bitcoin has broken out of a range and could be looking for a push to a fresh yearly high through $50,000,” said LMAX Digital in a morning note. According to Laurent Kssis, a crypto ETP specialist at CEC Capital: “This pump is driven by leverage, i.e the open interest on BTC contracts has increased by $982 million in less than 24 hours.” Kssis said he remains cautious, and the $40,000 level could be tested over the weekend. “But overall liquidation indicates a further small appreciation for BTC which will break the key 45k support barrier.” Ether also gained, adding 3% to a two-week high after asset managers Ark Invest and 21Shares amended their joint spot ETH exchange-traded fund (ETF) filing. The CoinDesk 20 rose 4%.