For investors in banks like Bank of America (NYSE: BAC) , JPMorgan Chase (NYSE: JPM) , and Wells Fargo (NYSE: WFC) , this has significant implications, as all of those institutions will make much more money if and when rates eventually rise. By contrast, while there aren't enough babies born in the United States each year to offset deaths, the population is still growing thanks to positive net immigration. The underlying assumption is that rates will at some point return to historically "normal" levels given inflation expectations over a long period of time.