Unique and proprietary data of the illiquid, one-year non cancelable for three month Bermudan swaps (1Y NC 3M swaps) and one-year non callable for three months Bermudan CDs (1Y NC 3M CDs), provides evidence of market efficiency. The 1Y NC 3M swap and 1Y NC 3M CD markets efficiently reflected unexpected economic information. The 1Y NC 3M swaption premiums also followed the European one-year into three-month (1Y into 3M) swaption volatilities. Swaption premiums were computed by pricing non-optional instruments using the quoted 1Y NC 3M swap rates and the par value swap rates and taking the difference between them. Swaption premiums ranged from a slight negative premium to a 0.21 percent premium. The average swaption premium during the study period was 0.02 percent to 0.04 percent. The initial swaption premiums were over 0.20 percent while the final swaption premiums were 0.02 percent to 0.04 percent. Premiums peaked and waned throughout the study period depending on market uncertainty as reflected in major national economic announcements, Federal Reserve testimonies and foreign currency devaluations. Negative swaption premiums were not necessarily irrational or quoting errors. Frequently, traders obligated to provide market quotes to customers do not have an interest and relay that lack of …