Lose of Principle in your CD or Money Market

You can't guarantee that what you are asking.

 The loss of principle is more basic than that.  CDs guaranteed against default, are low risk, and have a stated rate of return given to you even if variable, there is a benchmark or band rate.  Much like a bond, they must be left for maturity.

Here is the challenge:  You have a CD locked to an interest rate.  The market peforms better, so everyone actually earns more than you.  On top of that inflation takes a piece of your pie.  Inflation will kill any gains you have attempted, especially with low interest rates of CDs.

Money markets will give you a bit more of an edge, but not by much.

Best of luck. 

Perhaps English is not your original language; therefore --and I only want to be instructive and not impolite--, a point of English grammar, please: 

"Principal" is the correct spelling when one means capital or property; "principle" is correct when one means a rule of conduct or something that is inherent in anything, or is an established mode of action. 

Also, is it "loss" of principal --not "lose."

Thank you.