Eddie Adams / AP
The economy is growing just strong enough to avoid a decline, but not so strong that the Fed will tap the brakes (goldilocks). And for the first time in awhile, there's no obvious threat from abroad (China and Europe are not perceived to be particularly worrisome at the moment).
So what's there to worry about? Well, it seems like the big worry is simply the market itself, that it's gotten too expensive, and too complacent.
Dan Greenhaus at BTIG has a fascinating observation in his latest nightly note:
It was a very uneventful and quiet day with virtually all indices on either side of unchanged. The "information vacuum" we recently discussed was certainly in play today with virtually no macro data, no Fedspeak and no earnings of note. Generally, whenever there's a vacuum, it gets filled by something and these days, it appears to be those calling for not simply a market top but rather an outright bubble in equities. The WSJ ran three stories today, one worrying about growing inequality (a concern we share), another discussing "why internet stocks are getting too pricey" and a third characterized the level of stock and bond issuances as a "danger sign." There was the video "what to buy as the market tops" and a moneybeat column entitled "Frothy Asset Markets Now the Worry."
So there you have it. The worried are not economic or political or anything. All the talk is about the market itself, the valuations, and the risk of a bubble.