Funds in these accounts must be invested exclusively in U.S. stocks until the child turns 18. Investments in bonds are prohibited. Investments in international stocks are prohibited. This restriction forces a 100% U.S. equity allocation during childhood. Historical U.S. data since 1926 shows stocks outperformed bonds by about 5.5 percentage points annually on average. Research by Edward McQuarrie indicates that this level of stock outperformance is not representative of all U.S. market history. In earlier periods of U.S. history, stocks and bonds often produced similar long-term returns. Some historical 50-year periods saw bonds outperform stocks. Since 1926, a portfolio of 60% stocks and 40% long-term U.S. Treasuries returned approximately 9.1% annually over rolling 10-year periods. Over the same periods, a 100% stock portfolio returned approximately 10.7% annually. The return difference between a diversified 60/40 portfolio and a 100% stock portfolio was approximately 1.6 percentage points annually. Future outperformance of U.S. stocks is not guaranteed. The U.S. stock market has been the strongest-performing major market globally over recent decades, but continued U.S. market leadership is uncertain. 530A accounts require families to accept concentration risk in U.S. equities and exclude diversification through bonds and international markets.