The Bitcoin Flexible Leverage Index (BTC2X-FLI) allows users to leverage a collateralized debt position in a safe and efficient way. By abstracting its management into a simple index, it minimizes transaction costs and risks associated with maintaining collateralized debt. BTC2X-FLI makes leverage effortless for end users, eliminating the need for constant monitoring and high fees. It ensures fast transactions and responsive user interfaces even during times of high volatility. Users also don't have to worry about overpriced stablecoins or panic trading to save their positions. FLI automatically manages the liquidation ratio, reducing liquidations, even during black swan events. BTC2X-FLI offers advantages over Legacy Leveraged Tokens, including zero slippage, reduced rebalancing needs, and the ability to emergency deleverage during black swan events for additional fund safety.