JOJO is a decentralized perpetual contract trading platform building on Base Network, using an off-chain matching and on-chain settlement order book model. JOJO balances liquidity and composability, providing professional traders with a smooth, fast, low-cost trading experience and hedging capabilities for other DeFi protocols. JOJO is an exceptional choice due to its superior liquidity, low fees, innovative multi-collateral mechanism, cross-margin system, and flexible subaccounts. The Smart Contract Order (SCO) system ensures efficient trade execution with a hybrid liquidity model and an order book that combines off-chain matching and on-chain settlement. JOJO offers competitive fees, with a transaction fee of -0.01% for makers and 0.03% for takers, unmatched in the market. The multi-collateral feature supports various interest-bearing assets, allowing users to earn profits while trading. The cross-margin system enhances capital efficiency by sharing the same margin account across all positions. Additionally, JOJO's subaccount design caters to experienced traders by offering flexible asset management and multiple trading strategies.