A bond vigilante is a bond market investor who protests monetary or fiscal policies he considers inflationary by selling bonds, thus increasing yields. In the bond market, prices move inversely to yields. When investors perceive that inflation risk or credit risk is rising they demand higher yields to compensate for the added risk. As a result, bond prices fall and yields rise, which increases the net cost of borrowing. The term references the ability of the bond market to serve as a restraint on the government's ability to over-spend and over-borrow.