The S&P 1,500 is a very broad index. In fact, its constituent companies represent over 90% of the entire market cap of all US stocks. And, a frighteningly increasing number of them are the walking dead.
By design, the companies that index does not include are the smallest, riskiest, most-likely-to-fail public companies. So you’d think the ones left would predict a fairly robust corporate financial profile. These are, after all, the 1,500 largest public companies in America.
But imagine if, on a cross-country road trip, you pulled off the interstate and found yourself in a small town of just 1,500 residents. What would you say the prospects for that town would be if 225 (and rising) of them were the walking dead? Zombies who would collapse under their own weight if they weren’t kept barely shambling along on a steady diet of government-subsidized brains?
While just a far-fetched tall tale for a town, in a rotting nutshell, it is very much the reality for the US stock market today. Believe it or not, 225+ of the largest and supposedly most successful companies are so operationally sick, so incapable of supporting themselves in any way, that they’d be bankrupt in a heartbeat without the zero interest rate policy (‘ZIRP’) loans that amount to a handout from the Fed. Without their corporate-welfare zombie brains.
As Mike Maloney explains in his most recent sweeping economic update, these companies are hollow shells that only appear healthy from a great distance: 
Their debt burdens, bloated over a decade of borrow-‘til-you-bust, ultra-low-interest-rate policy, are so large, and their ability to generate cash flow is so poor, they can’t afford interest-only payments on that debt. Forget paying back any of the principal.