"I'm incredibly focused. I've got something to prove," the billionaire told a room full of hedge fund managers and investors at the annual SkyBridge Capital industry conference in Las Vegas, known as SALT.

Ackman suggested that after his fund's downturn, he is now ready for a comeback, saying that chief executives who have recently suffered setbacks after otherwise strong careers are often great to bet on.

For Ackman, that setback was an ill-fated bet on Valeant Pharmaceuticals International Inc (>> Valeant Pharmaceuticals Intl Inc). Ackman bailed out of the stock in March, but not before it played a big role in two years of double-digit portfolio losses for his $11 billion hedge fund firm Pershing Square Capital Management.

Ackman's portfolio of stocks is posting gains this year, and he said he is likely to add at least two new market bets that are similar to the firm's early winners.

"The next investment you will hear from us isn’t going to be some successful company trading near its highs," Ackman said. "It’s going to be a huge opportunity for efficiency, better deployment of capital, a change in strategy, some management changes needed, but the business quality is going to be extremely high."

Ackman was candid about the lessons learned from his investment in Valeant, which he made in early 2015 and then spent some 18 months trying to rescue the struggling company before walking away with a multi-billion-dollar loss.

"We picked the wrong business for us," Ackman said, adding that he had not expected Valeant's business to be as unstable as it turned out to be and that he relied too heavily on management.

"When you put your hand in the fire and you get burned, you go back to a real focus on your core," he said. "Actually, selling Valeant was one of the best things we did."

Ackman has often helped engineer successful management shake-ups, including at Air Products and Chemicals Inc (>> Air Products & Chemicals, Inc.) and Canadian Pacific Railway Ltd (>> Canadian Pacific Railway Limited).

Despite his recent struggles, Ackman was one of the stars of the four-day industry confab. The roster of speakers also included fellow billionaire hedge fund investor Daniel Loeb, private equity titan David Rubenstein and former Federal Reserve Chairman Ben Bernanke.

On Thursday, Ackman praised the chief executive officer of Chipotle Mexican Grill (>> Chipotle Mexican Grill, Inc.), one of his more recent investments, calling Steve Ells "outstanding." Late last year Ells became Chipotle's sole CEO after his co-CEO, Monty Moran, left the company.

Ackman is known for courting publicity for his activist investments but has shrouded his more recent bets in mystery, saying on a recent conference call with clients that one new investment has already risen 30 percent and that another, which he also did not name, had already been sold.

As an activist investor, Ackman frequently gives advice, sometimes unsolicited, to chief executives.

On Thursday he had suggestions for President Donald Trump, saying that Trump should focus on infrastructure projects like rebuilding bridges and railroads, instead of trying to tackle healthcare reform. "He's got to have a win," Ackman said.

(Reporting by Svea Herbst-Bayliss and Lawrence Delevingne; Editing by Leslie Adler)

By Svea Herbst-Bayliss and Lawrence Delevingne