Money-market rates have been under pressure all year as a result of the Fed's policies.
There's uncertainty about when the Treasury is set to exhaust its borrowing authority under the debt ceiling.
Investors are wondering if and how the Treasury can slash its giant cash pile.
As low yields may push money market fund returns negative, there aren't enough places to put cash.
It's adding fuel to a debate about what the Fed should do with its various tools to keep a rein on policy.
The front-end of the U.S. fixed-income market has been awash in cash.
The U.S. debt ceiling is slated to be reimposed in July.
The effective federal funds rate has held steady at 0.07% since Feb. 18.
Securities maturing next week are already trading at negative levels in the secondary market.
Swings in the government’s cash on deposit at the Fed have a direct impact on the level of reserves.