For many years, Government of Canada bonds with high coupons traded at much higher yields than those with lower coupons. This apparent market inefficiency virtually disappeared over a short period of time during 1993. Several events occurred in 1993 which relate to the narrowing of the spread. This paper shows the earlier yield spread to be consistent with restrictions on the trading of strip bonds. It also finds it difficult to defend the hypothesis that the higher yield spread represented unexploited profit opportunities.