With a great influence on the 1920’s stock market boom, he discovered that stocks had a hidden advantage over bonds in the long run. Its success enabled Smith to launch a mutual fund firm, "Investment Managers Company." Common Stocks as Long-term Investments is a collection of failed studies to prove the theory that to protect purchasing power, bonds were better investments than stocks during deflation, while stocks were better than bonds during inflation. It states that the value of bonds may change due to changes in the credit quality of the company or changes in demand in relation to the maturity/yield of the bond.