While none of these portfolios is likely to produce particularly inspiring returns — a function of already elevated valuations for both U.S. stocks and bond — the difference between the two extremes is still important.
Those differences are informative, because they highlight points where market valuations — instead of normalizing — reached historic extremes at the end of the 10 - year projection horizon (1974, 1998 - 2000 and 2015, respectively).