According to Michaël van de Poppe, the traditional 4-year cycle in cryptocurrency markets may not be as reliable as previously thought. He asserts that the anticipated altcoin bull market has not occurred, and instead, the bear market has been the longest to date. Van de Poppe suggests that the peak of this bear market is not expected within the next six months, challenging the conventional cycle duration. This insight is critical for traders considering altcoin investments, as it suggests a need for revised strategies based on extended market analysis.