Say goodbye to sunny skies and ditch the rose-colored glasses.

That's the collective advice of the investment seers who populate the Barron's Roundtable, and whose market forecasts for the back half of 2014 range from meh to feh. Specifically, the bulls in the bunch see a meager 5% gain in the Standard & Poor's 500 in the months ahead, while the rest see a volatile rout in late summer that could leave stocks 10% lower, at least.

Equities...