In short, we are required to gather this information by federal law. The SEC, via the 2001 USA PATRIOT Act, requires all financial institutions to verify and record your Social Security number in order to verify your identity. This helps identify and prevent potential terrorists and money launderers from gaining access to the stock markets.
Additionally, we need your SSN in order to issue you a tax reporting form each year. You can learn more about these requirements from the SEC here.
Rest assured all your personal information is always encrypted and never accessible or visible to anyone within Public that is not licensed by FINRA to do so.
If you ever have questions, Member Support is always here for you via chat in the app or by email to email@example.com