As the Federal Reserve winds down its third round of unprecedented stimulus, one thing has become increasingly clear in the bond market: the U.S. economy just isn’t going to grow enough to upend demand for Treasuries.

While more than $3 trillion of debt purchases since 2008 have helped the U.S. recover from its worst recession in seven decades, bond-market indicators for long-term inflation, growth and funding costs are all lower now than they were at the end of the central bank’s first two rounds of quantitative easing.