If you would have purchased a 12 month CD 1 year ago vs. floating in a variable rate account (compounding w/ money market fund), you would have lost yield.

http://www.bankrate.com/brm/graphs/graph_trend.asp?tf=360&ct=Line&prods=50&gs=400,220&st=CA&c3d=False&web=brm&cc=1&prodtype=D

If you are convinced rates will continue to rise or remain stable, why would you lock your rate? – Especially with an inverted yield curve.