What is compound interest? Compound interest is often called one of the most powerful concepts in finance. Find out what it is and how it can work for you. For more content related to Compound Interest, check out: Understanding The Time Value Of Money http://www.investopedia.com/articles/03/082703.asp Overcoming Compounding's Dark Side http://www.investopedia.com/articles/06/compoundingdarkside.asp