Bitcoin as the most resilient collateral worldwide, while DeFi has built the most transparent financial infrastructure to date. But in reality, the amount of Bitcoin flowing into the DeFi ecosystem is pitifully small. This huge mismatch is not just a current situation but also hides a seriously underestimated growth gap. As on-chain finance becomes more accessible and cross-chain bridging matures, the integration of BTC and DeFi is only a matter of time. Whoever seizes this wave will hold the key to the next round of wealth redistribution.