The U.S. stock market is off to its worst start ever — down nearly 12 percent in just three weeks. Standard & Poors searched records back to 1897 and couldn’t find anything worse.

While the market has been drifting lower since summer — including a brief but scary decline in late August — this drop has seemingly come out of nowhere and is unremitting in its furor.

Yesterday, the Dow dropped 550 points by midday before rallying sharply. While there are always things to worry about, this seems to be the bear market about nothing.

The Chinese economy, the second largest in the world, may be getting unhinged. And the oil market has gone from boom to busted in 18 months but hey, nobody’s perfect.

If it weren’t for these minor issues, the outlook might seem bright. Job growth has been strong in the U.S. and corporate balance sheets are in the best shape in years.

Worldwide, corporations and investors are awash in cash and looking desperately for places to stash it (no place more frantic than Colorado where legal marijuana growers can’t access the banking system).

So what’s an investor to do? It’s usually best to hunker down and not panic. And if you feel like panicking, turn off the TV and the Internet and take a walk. You’ll feel better and in the long run, your portfolio will thank you.