According to CryptoMichNL, many traders are planning to sell their altcoin holdings in the current month of 2025, driven by expectations around the Bitcoin 4-year cycle and historic price movements. The source emphasizes that time-based profit-taking could result in selling at local lows, as historical data suggests altcoin prices often recover after such periods. For trading strategies, investors should carefully assess the timing of their altcoin sales and consider market cycles rather than relying solely on calendar-based actions (Source: Michaël van de Poppe, Twitter, May 25, 2025).