Should I move my money from my savings account?

I am a 22-year-old student beginning my PhD next year. I have recently acquired ~$18,000 that I do not need at the moment. It is sitting in my savings account right now earning 4.25% interest. I am not planning on marrying or buying a house for at least another 5 years, but I would like the money to be somewhat available just in case things change. I am more concerned with ensuring that I don't lose money than with it growing significantly. Should I keep it in the savings account or look into mutual funds, stock market, etc? Canada Savings Bonds currently have a lower interest rate than my savings account, so that doesn't make sense to me. Thanks for your input.

i would advise you to ladder it in to cd"s with expire dates of 12, 18, 24, 26, and 32 months that way should the need arise you will have a hunk of money coming in every 6 months and when they do come due if you do not need the money roll it over and if possible add to the investment!!!