According to @CoinMarketCap, Bitcoin (BTC) closed 2025 below its opening price, the first time a post-halving year has finished down, raising questions about the four-year halving cycle, source: @CoinMarketCap on X, Jan 1, 2026. This confirms a break from the historical pattern seen in prior post-halving years and provides a new data point traders must incorporate into seasonality and cycle-based models, source: @CoinMarketCap on X, Jan 1, 2026.