The S&P 500 has practically doubled since 2015, which scares some investors who can’t believe their luck and see the economy hitting a hard wall. That’s not really the problem.

Do the math and earnings for big companies are up about 90% since December 2014. I’m using that reference date for two reasons. First, it was the post-2008 zero-rate era ended in 2015, which meant Corporate America no longer had free money to play with.

And the second reason is that 2015 was the last “secular” earnings recession that didn’t involve a global pandemic. The transition from 2014 to 2015 was a bad one, setting up the trade war and all the other turmoil stocks had to absorb after that.

But even starting the period with a 15% drop, earnings have expanded in most years. Big companies get bigger. And as a result, while stocks are 90% above where they were in late 2014, break that price down and per dollar of profit, they’re exactly where the earnings trend says they should be.

So if you keep looking over your shoulder waiting for the bottom to drop out of the market, consider this: valuations have not blown out. There’s no more hot air in the market now than there was nearly 10 years ago.

If you were afraid of the S&P 500 at 2000, you’re probably not reading this now. The rest of us have gotten to participate in Corporate America’s tremendous expansion. Investors deserve what we’ve earned.

Admittedly, the Fed accelerated the cycle in recent years and is now hitting the brakes hard. Last year, when the market was still racing to record levels on a zero-rate high, the S&P 500 reached a level 135% above where it was back in 2014.

That was obviously too far to go when earnings could only support about two-thirds of that giddy ascent. We’ve given up the other third now, leaving earnings growth and market returns balanced over the period.

What does this mean for anyone but historians? Past success is deserved. The market has earned its right to trade roughly where it is today, despite the Fed and everything else.

The question is where you think the world goes from here. I’m not convinced that the S&P 500 has what it takes to double earnings in the coming decade . . . the numbers are now simply too big.

These big companies need to find another $2 trillion in profit to make that happen. That’s still a lot of money. Apple (AAPL) alone needs to be earning $200 billion a year to play its role in that story.

I’m not picking on AAPL here but where does that money come from? Services is the only hypergrowth segment there right now, and it needs to expand 20% a year ever year for the next decade to hit the target.

Apple Services is growing 14% a year now. It’s already falling short. Now multiply this math, one way or another, by 500 big stocks.

The S&P 500 is what’s hitting a growth wall. The U.S. economy, on the other hand, has never stopped innovating and expanding. Find the growth spots and your future can look as good as the past.

Leave the index alone to find its own destiny. If your companies aren’t growing their earnings by at least 8% a year, you’re losing the future. And that’s what matters, right?