Over the next nine years, they wouldn’t have to triple again, but they would need to perform pretty sensationally. Moreover, there won’t be the huge tailwind from declining interest rates that drove the 1982-1999 bull market.
So it would have to be triggered by some other development. What could it be? Breakthroughs in medicine and longevity? Possibly.
Millennials are finally taking over the economy and spawning changes we can’t imagine? Certainly that would have to happen. And they will take over the economy, if they haven’t already, whether or not the bull market extends its run.
There is one outcome we can predict with more certainty. As the U.S. approaches the end of the decade and baby boomers finally start to retire, the labor market is going to start running low on workers. That should mean that incomes will rise and baby boomers who didn’t save enough for retirement can find part-time jobs working for their kids.