Can you please explain what margin trading is in the context of BingX, and how it differs from traditional trading? I'm particularly interested in understanding how margin works in enhancing the potential returns, as well as the associated risks and considerations that traders should keep in mind when using margin on BingX. Additionally, how does BingX calculate and manage the margin requirements for its traders, and what measures does the platform take to ensure the safety of traders' funds while engaging in margin trading?