There is a selloff so the price is lower. Bonds pay an interest (in coupons). There is the face value (par). But you don't buy/sell bonds at face value, you buy them at market value. So what's interesting is the yield = coupon amount / market price (or just price).
Relative to other bonds US treasuries are a lot less attractive today.
But the price is not that simple. Since bonds are paid periodically, the market price factors in the next coupon. Would you buy a bond at the same price 1 day before paying coupon than the day after? Of course not! So market price is called "dirty" because it has the next coupon implicitly considered. There are different ways to make it a "clean" price, depends on the country.
Relative to other bonds US treasuries are a lot less attractive today.
http://www.investopedia.com/university/bonds/bonds3.asp
http://data.cnbc.com/quotes/US10Y
But the price is not that simple. Since bonds are paid periodically, the market price factors in the next coupon. Would you buy a bond at the same price 1 day before paying coupon than the day after? Of course not! So market price is called "dirty" because it has the next coupon implicitly considered. There are different ways to make it a "clean" price, depends on the country.