Don't most mutual funds charge an early redemption fee? My Schwab accounts charge 2% if transfers/redemptions occur within 30 days. Being able to move in and out to another fund and then to G Fund within a calendar month is better than most mutual funds allow, no?
HFT and free riding is a big frowny face in the industry, but in essence one can do that with TSP. The 12pm cutoff makes it a challenge, but are there funds out there that allow HFT and free riding? The SEC is not supposed to allow that and that's one reason why I have not rolled over my TSP to another investment company.