Something to worry about

Stock market investors don’t seem worried about bonds. Since the beginning of May, the yield on the 10-year US Treasury bond has increased by one-half a percentage point, to 5.1%. But while stocks have tumbled on the bond market’s especially bad days, the S&P 500 index is up by 3% over the period. Stock market optimists argue that the higher yields are a good sign for equities. They say the sellers of bonds will soon be buyers of shares. Also, bond yields may be up because US growth prospects a...