Bitcoin surged in April, but its run could be on shaky ground, according to crypto data provider CryptoQuant. The flagship crypto coin gained 12.7% for the month, registering back-to-back monthly gains and its best month since April 2025. It eked out a nearly 2% gain in March, following five consecutive down months. Ether gained 8% in the same period, also its second up month in a row and best month since August. Perpetual futures — the dominant source of leveraged crypto trading activity — was the "sole driver" of the rally, however, according to CryptoQuant. The firm's apparent demand metric, which tracks the 30-day change in outright purchases of bitcoin, stayed negative throughout April while futures demand rose. The two trends combined are often a warning sign, according to Julio Moreno, head of research at CryptoQuant. They suggest the upward price action is fueled by speculation rather than fundamentals.…