Subject: Re: Treasury Bond Yields Tank
The drop in 1-month rates started in the secondary market around March 10th. There are 2 possible causes discussed in the comments following Wolf's article. One idea is that possibly in about a month there will be a debt ceiling crisis, and this might trigger massive stock market losses. Investors want cash available when that happens, and so only want to lock in 1-month of Treasury.

The alternative cause is businesses moving their cash from bank accounts to 1-month T-bills. Silicon Valley Bank failed after a bank run on March 10, 2023. I think this fits the data better.