Bitcoin's market dominance is currently testing the 58% support level, a critical threshold that has historically preceded altcoin rallies. Analysts suggest that a breakdown below this level could herald a 'true altseason,' with dominance potentially falling to 44% by mid-2026. Technical indicators such as RSI and MACD indicate weakening momentum, hinting at a possible capital shift towards alternative cryptocurrencies. While the 58% level has held so far, historical trends suggest a decline could occur if this support fails.