Transaction costs not only depend on the size of the spread, but are also closely related to the account type, execution mode and capital guarantee mechanism. The cost trade-offs between standard accounts and low-spread accounts have different emphasis. STP/ECN and market-making models determine the interest relationship between the platform and traders, while customer fund isolation, regulatory constraints and investor protection constitute a multi-layered safety bottom line. Before choosing a platform, first look at these three dimensions clearly.