To manage other people money from non-US citizens/residents. By the way, I'm also not a non-US citizen or resident. If they open a personal account with a US broker, and they sign a local power of attorney, agreement and contract (registered with the local regulatory entity): Is that enough so I can't be SUED IN THE UNITED STATES? If anything goes wrong. I'm a conservative investor, but you never know... I won't mind much being sued locally.