The blowout U.S. jobs report for October means the FederalReserve may be weeks away from raising interest rates. For U.S.savers earning next to nothing on $2.6 trillion of money-marketmutual funds, the move will barely register.

The reason is that there's an unprecedented shortfall in thesafest assets, especially Treasury bills — a mainstay of moneyfunds and traditionally the government obligations that are mostsensitive to changes in Fed policy. The shortage means some keymoney-fund rates will probably remain near historic lows even ifthe central bank increases its benchmark from near zero nextmonth.

The phenomenon is a consequence of regulators' efforts to curbrisk after the financial crisis. Money-market industry rules set totake effect in October 2016 may lead investors and fund companiesto shift as much as $650 billion into short-maturity governmentobligations, according to JPMorgan Chase & Co. Meanwhile, theamount of bills as a share of government debt is the lowest sinceat least 1996, at about 10 percent, and the Treasury is justbeginning to ramp up issuance of the securities after slashing itamid the debt-ceiling impasse.