What if a single chart signal could predict Bitcoin's next major crash? A historically accurate warning sign that preceded every major Bitcoin bear market since 2012 has just flashed red again. This key momentum indicator, the monthly MACD, suggests the recent bull run has ended, signaling a major trend reversal. In 2022, this same signal appeared just before prices crashed from over $50,000 to below $20,000, with similar patterns kicking off the deep bear markets of 2018 and 2014. This isn't just a technical blip; it’s a potential long-term shift reinforced by macro risks and recent ETF outflows. For traders, this is a critical alert to prepare for downside volatility, watching key support at $84,500. For investors, it’s a prompt to re-evaluate risk and potentially hedge positions.