Net Net: Promoting innovation and managing change
The Breakers Palm Beach resort in Palm Beach, Fla., is shown in this aerial view.
Steve Sanacore

Six hedge fund managers gave their best investment ideas at an exclusive—and private—conference, including new bets against companies.

The investors were part of a session to present one long and one short idea each at Morgan Stanley's "Breakers" conference, put on annually by the bank's hedge-fund-servicing unit at the posh Breakers Hotel in Palm Beach, Florida.

Read MoreHere are the best hedge funds for 2015: Experts

The event Wednesday was private and closed to the media, but a person in attendance shared the recommendations with, along with a summary of the rationales. The picks were:

Aaron Cowen of Suvretta Capital Management: Long pick: Adobe Systems. The company's new subscription-pricing model should work and will help improve profitability, but that isn't being priced in to analyst estimates. Short pick: Target. Extra consumer cash from low oil prices will boost sales, but it will help low-cost retailers like Family Dollar Stores more. Margins are high compared to Wal-Mart Stores and there's no growth in the number of stores. Target price for the stock is in the high $50s or low $60s.

Daniel Lewis of Orange Capital: Long pick: Amaya Gaming. Amaya's purchase of PokerStars gives it leading market share. It also has low taxes from its base on Isle of Man. New PokerStars management is good and the stock is worth more than $50 a share. Short pick: MGM China. Trends in Las Vegas have been good, making it relatively cheap compared to Chinese gambling hub Macau (as a pair trade, Lewis also likes regular MGM stock long).

Kurt Billick of Bocage Capital: Long pick: Lundin Mining. The copper, zinc and nickel miner is poised to benefit from recent investments in its business. Short pick: natural gas. It's still overvalued at $3 per million British thermal unit given there's not enough storage in the U.S. Prices will fall below $2 per million Btu.

Glen Kacher of Light Street Capital: Long pick: 21Vianet. The company is growing well and is trading at a discount to Equinix but with a much higher growth rate. Short pick: Youku Tudou. Competitors are being run as loss leaders to attract new users, making it difficult for Youku, the YouTube of China, to compete and be profitable. The bull case is it will be bought out by Alibaba, but it won't because it would have to consolidate the losses.

Anthony Bozza of Lakewood Capital Management: Long pick: American Capital. The business development corporation trades below net asset value. It has a corporate restructuring later this year and will split into multiple businesses. There's a more than 40 percent to 50 percent upside. Short pick: Arista Networks. The company faces steep competition from Cisco and others, which is destroying margins.

John Pinkel of Indus Capital Partners: Long pick: PICC Property & Casualty. Premiums should rise in China, up 15 percent a year for the next 10 years. Short pick: Belle International. Margins of 20 percent on footwear are too high, and there's lots of competition from Alibaba's Tmall and other e-commerce companies.

'Smart' money finds energy
'Smart' money finds energy

Read More From hedge funds to juice, and back again

A spokesman for Morgan Stanley declined to comment. A spokesman for Orange Capital confirmed the summary of Lewis' picks but declined further comment. Spokesmen for Lakewood, Light Street, Bocage and Suvretta declined to comment. Indus did not respond to multiple requests. Reps for the companies shorted did not respond to requests for comment, except for Target, which declined.

The Breakers conference is one of the most prominent annual gatherings in the hedge fund industry, offering Morgan Stanley's hedge funds clients a chance to show their smarts to potential investors also in attendance.

Well-known money managers who attended this year, according to the person inside, included Larry Robbins of Glenview Capital Management, Jim Chanos of Kynikos Associates, Paul Tudor Jones of Tudor Investment, Dan Och of Och-Ziff Capital Management, Andreas Halvorsen of Viking Global Investors and James Dinan of York Capital Management.

The investor Barton Biggs described the Breakers event as "fabled" in a 2006 memoir, Hedgehoggng.

"This conference is widely considered the prime event at which to raise money because it attracts the biggest, richest collection of hedge fund buyers in the world," wrote Biggs, who died in 2012.

Read MoreHedge funds swarm Davos