Billionaire hedge-fund manager Bill Ackman told CNBC on Monday he should have bet against the retail sector.
"We should've been" short on retail, said Ackman, CEO of Pershing Square Capital Management, adding his firm isn't really big on short selling.
"I see [that] retailers have to adapt," Ackman said in an interview on "Halftime Report."
The SPDR S&P Retail ETF (XRT) is down more than 8 percent this year. Major department store chains have scaled back their physical footprints as consumers' shopping preferences change.
When asked whether the mall will exist five years from now, Ackman, who has made a handful of retail investments over the years, said: "Yes."
"It's going to have different tenants, in 5 and 10 years from now," he said. He said the mall will adapt to become places where communities come together.
"Think about what a mall is. A mall is 100 acres at the intersection of the two most important highways in a particular community," he said. "It's going to be more food and entertainment and innovative concepts."
Ackman said "the old way of doing business" in retail isn't working anymore. "If you're selling a commodity product which is less convenient than ordering on Amazon, you're dead," he said.
If retailers want to survive the new consumer landscape, they need an innovative concept, Ackman said.
"You have to make an experience that people are excited about participating in," Ackman said. "People don't want to go to a big-box department store anymore."