I got that same letter back on 11/17/23 asking for the source of funds for my deposits. I had loaded $92k worth of $200 VGCs in about 6 weeks back in Sept/Oct without withdrawing anything, rather I left all the funds stashed in their 5% APY Savings acct to earn interest. I managed to string them along for another 2 weeks until the Nov interest payment hit around 4AM EST on 12/1, and then I immediately ACH'd all my funds out (except I left a few cents in there just to screw with them), and they shut my acct 9 hours later. Just got an e-mail last week that a check was in the mail for $0.03. Was a great little run while it lasted!!