DoubleLine Capital's portfolios have the shortest duration in their history, the fast-growing fixed-income manager's CEO Jeffrey Gundlach told more than 600 attendees at an alternative investment conference in Denver.

Gundlach voiced his skepticism about the U.S. government's ability to resolve its problems. The nation had spent the last 30 years borrowing money and distributing it to the wealthy or just squandering it, he argued.

There is so much uncertainty in the world that he discussed a portfolio he designed for black swan events. Among his picks were shorting Apple shares. "Google Google's price projection in 2007 and then look at Apple," he said, implying they were nearly identical. "How many people are going to keep buying the iPhone 8 or the iPhone 9 or the iPhone 12?"

He remains very bullish on natural gas for the long term, even though it's up 50% since he devised the portfolio back in April.

Another investment he favors as an inflation hedge is the Spanish equity market index, the IBEX. "The IBEX takes off like a scalded dog whenever there is a hint of inflation," Gundlach declared. Moreover, if Spain goes "kaboom," the battered IBEX will drop 65% but the pricey Standard & Poor's 500 could drop 75%.

-Evan Simonoff