Companies are borrowing $74 billion in the U.S.investment-grade bond market this week, the most for any comparableperiod since records began in 1972. Since Tuesday, corporationsincluding Coca-Cola Co., Walt Disney Co., and Apple Inc. have soldnotes as yields have dropped. And the frenzy isn't letting up.

At least another $50 billion is projected for the rest of themonth, and the activity is spilling over to junk bonds andleveraged loans as well. With more than $16 trillion of bonds inEurope and Asia paying negative yields, investors worldwide aresnatching up debt that offers relatively higher returns, keepingdemand strong in the United States.

"This is a great time for companies to refinance," ChristianHoffmann, a portfolio manager at Thornburg Investment Management,said. "Financing costs are near all-time lows, so I would not besurprised to see better high-yield companies coming to market andtreating debt capital markets like a cheap buffet."