TSP Center

The G fund can yield more than .01 percent per day...depends on the rate of return for that month which is determined on the last business day the month before. " The G Fund rate is calculated by the U.S. Treasury as the weighted average yield of approximately 130 U.S. Treasury securities on the last day of the previous month." Source:
https://tspsmart.com/TSP-G-fund#:~:text ... utstanding.

As of March 2023, the TSP G Fund interest rate is 4.125%.

https://www.tspfolio.com/tspgfundinterestrate

I'm not a subscriber of that site. I just get the rate there every month.

It says that "The goal of the (G) fund is to maintain a higher return than inflation." I don't remember any time that the G fund has done any better that the rate of inflation, but still 4.125% is probably better than you could get at any bank.