Bitcoin serves as the denominator in crypto markets. When you measure asset performance, market cycles, and risk appetite across the industry, everything gets benchmarked against BTC's price action and dominance metrics. A rising Bitcoin typically signals risk-on sentiment, while pullbacks often trigger portfolio rotations away from altcoins. This reference point works regardless of whether you're analyzing DeFi protocols, layer-2 networks, or emerging blockchain projects—Bitcoin's correlation with the broader market remains the foundational metric. Traders use it to gauge cycle tops and bottoms. Institutions reference it for macro exposure. Even smaller projects track their BTC pair performance to understand true market sentiment versus noise. That's why Bitcoin doesn't just function as a store of value or payment mechanism; it operates as the industry's primary denominator for valuation, cycle analysis, and systemic health.