Current yield is a commonly quoted yield calculation used to evaluate the return on a bond for a one-year period. It only accounts for the interest or coupon payments that the bond returns to investors. This yield is calculated by dividing the bond's coupon rate by its current market price, but it does not account for any capital gains or losses when the bond is sold. If the bond is not sold within the year, this yield calculation will provide the bondholder with an accurate assessment of his or her return.
The only way a bond's current yield could be negative, using this basic evaluation, is if the investor was receiving negative interest payments, or if the bond somehow had a market value below $0 – both of which are very unlikely to occur.