What do you call a hedge fund that doesn't hedge?

The latest growth area for the industry.

On the heels of a multiyear market rally, a slew of hedge-fund firms are launching "long-only" funds betting that at least some stocks have further to climb. The moves come amid a brutal stretch for short bets against companies, traditionally a key strategy for hedge funds.

The new funds also represent a shift by hedge-fund managers—known for their sophisticated tactics and exclusivity—into the kind of old-fashioned stock picking more associated with Main Street mutual funds.

But some wonder if the latest craze is merely a grab for fees, or perhaps even a sign of the top of the stock market.