The lawmakers' letter comes as the SEC is facing increasing pressure from the crypto industry to clarify its regulatory stance on crypto custody. In recent months, several crypto companies have announced plans to offer custody services for their customers, but they have been met with resistance from the SEC, which has raised concerns about the security of these services. The lawmakers argue that the SEC's guidance is outdated and does not take into account the recent developments in the crypto industry. They also argue that the guidance is creating uncertainty for businesses that are looking to offer crypto custody services. The SEC has not yet responded to the lawmakers' letter. However, it is expected that the agency will soon release new guidance on crypto custody.