If in addition to the 5 major asset classes (cash, long-term Treasury bonds, gold, U.S. large-cap stocks, and real estate), add another 5 stock indices: U.S. small-cap stock index, European stock index, Japan stock index, Asia-Pacific emerging market stock index, and Latin-America stock index.
Again, allocate equal capital to the two ETFs with the highest values of the "Investment Value Index". The equity growth curve of the new ETF Investment System model from January 2003 to August 2014 is as follows:
With small increase of volatility, ETF Investment System Of 10 Assets enhances annual return percentage from +14.5% to +18.4% (equity increased to 7 times in 11.5 years). Therefore, the advantage of the new ETF Investment System is obvious.