There is no question that we have been in a secular bull market for many years (since 2009 by my count). The question is whether it will eventually end with a whimper or a bang. The 1982-2000 secular bull ended with a loud bang in the form of the dot.com bubble, while the 1949-1968 bull ended with a series of modest new highs followed by increasingly large drawdowns. You can see that nuance in the chart below.
So far, the current secular trend seems to be following the 1960s analog more than the late 1990s, and the CAPE model suggest that over the next few years the return profile will accelerate before the secular wave crests.
While this secular bull is getting long in the tooth at 16 years old, the analog to both the 1982-2000 and 1949-1968 super-cycles shows that there could be a few more innings left, pushing the market to ever new highs. Per the regression trend lines below the two historical analogs are a very close fit to todays market.
