Inflation and Your Portfolio Even low inflation rates can pose a threat to investment returns. Share | Related Content The Rule of 72 Do you know how long it may take for your investments to double in value? The Rule of 72 is a quick way to figure it out. The Great Debate Continues: Active vs. Passive In investments, one great debate asks the question, “Active or Passive Investing: Which Is Better?” Saving for College This calculator can help you estimate how much you should be saving for college.