The price of bitcoin hit a 2019 high on Friday, but the gain may be less about demand for bitcoin and more about problems at the embattled exchange Bitfinex.

Bitcoin traded as high as $5,791 on Friday, according to CoinDesk, up about 7% on the day and the highest price since November. Its price has been steadily rising since last week, when the New York attorney general’s office said Bitfinex had covered up a loss of $850 million worth of corporate and customer funds using the reserves of the digital currency it controls,...