When bond yields rise, their prices fall, eating into any gains from the security's coupon.

ECONOMIST: Finance after the crisis

Tipping points are clearest when bond yields rise sharply, as they have in Greece, Ireland and Portugal, making their debt too expensive to keep rolling over.

FORBES: The Enemy Within

Bond yields rise when prices fall.

WSJ: China Probe Focuses on Trading of Bonds

Yields fall when bond prices rise.

WSJ: Vanguard Bond Index Fund Beats Stars Bill Gross, Dan Fuss

That is, when yields rise the price or value of bonds declines, and in the other direction, when yields are falling, bond prices rise.

FORBES: Might Be A Great Time To Be A Bond Bear

At best there is a precautionary case: without fiscal tightening, the Tories fear, bond yields are bound to rise, especially when the Bank of England stops buying gilts.

ECONOMIST: Tightening economic policy

Dehn calculated that investors now holding a 10 year Treasury when yields rise to 6.5% from the current level will lose 34% on the bond price.

FORBES: When Flight To Safety Is Risky

The increasing likelihood of a bailout agreement between Hungary and the International Monetary Fund have pushed Hungarian bond yields, which decline as prices rise, to around 7% from about 10% last year when Legg Mason first bought in, Mr. Smith says.

WSJ: Tiny Countries' Markets Are Looking Good