The best value proposition at the moment is in the 6-month bill. Let's take this week's auctions for a simplistic example.Saw Suzie Orman today on Morning TV touting short term treasuries, 3 months in particular. She says rates are still going up and that one should not lock in too long.
The 13 week T-bill paid 4.693% and the 26 week paid 4.865% this week. That's a differential of 17.2 basis points which means 13 weeks down the road the yield on the rolled over 13 week T-bill would have to be at least 5.037%. Could that happen? Sure. Will it? I have no idea and neither does Suze.
I'll happily take my chances on the 26 week T-bills.