Bitcoin, as the most resilient collateral worldwide, has paved the way for DeFi to build the most transparent financial infrastructure to date. However, in reality, the amount of Bitcoin flowing into the DeFi ecosystem is surprisingly small. This huge mismatch is not just a current situation but also hides a seriously underestimated growth gap. As the barriers to on-chain finance gradually lower and cross-chain bridging becomes more mature, 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.