According to @rovercrc, BTC illiquid supply has reached new all‑time highs, suggesting more coins are held by entities that rarely sell and implying tighter available float for spot markets (source: Crypto Rover on X, Sep 20, 2025). Illiquid supply refers to coins controlled by holders with minimal spending history, a metric widely used in on‑chain analytics to gauge available float (source: Glassnode Academy, illiquid supply definition). Historically, increases in illiquid supply have coincided with falling exchange reserves and thinner spot liquidity, conditions that can amplify slippage during volatile moves (source: Glassnode research on illiquid supply vs. exchange balances; source: CryptoQuant, Exchange Reserves metric; source: Kaiko research on market depth and slippage). For trading, monitor BTC exchange balances for outflows, spot order book depth across major venues, and spreads to assess liquidity conditions and adjust order sizing and execution tactics accordingly (source: CryptoQuant exchange reserves dashboard; source: Kaiko spot market depth and spread data).