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. Share | Related Content From Boats to Brokers From the Dutch East India Company to Wall Street, the stock market has a long and storied history. The Ivory Tower Changes Wall Street Thanks to the work of three economists, we have a better understanding of what determines an asset’s price. Impact of Taxes and Inflation Estimate the potential impact taxes and inflation can have on the purchasing power of an investment.