The ten-year treasury yield has been rising for almost two weeks - which means that the price has been falling.
http://stockcharts.com/h-sc/ui

Investors who bought at the highest recent price less than two weeks ago have lost about 1.5% of their principal. Their small coupons (1.62%) will not cover this loss if it contimues at this rate.

There may be more pain ahead for bondholders. Some of them may retreat into equities.