Follow Jim Rogers? Why this dollar 'bear' is buying greenbacks now.

Investor and author Jim Rogers is known for his pessimism about the dollar, given high levels of US debt. But he said Friday that he's buying them now in the short term. What gives?

When investor Jim Rogers talks, people listen. On Friday he talked a lot, saying that despite his pessimism about the US dollar he's become a buyer of greenbacks during what he expects will be a short-term rally.

But he also said that other US investments, such as stocks, look too risky to hold. Mr. Rogers is actively betting that US technology stocks and one "big, big, big" American bank will go down in value.

In comments during an interview with Tom Keene on Bloomberg Television, he declined to name the bank. The dollar was rising as he spoke.

Oh, and for good measure he said both President Obama and Federal Reserve Chairman Ben Bernanke should resign.

"The fundamentals are horrible for the US dollar," Rogers said, citing a soaring national debt and Fed policy that results in near-zero interest rates for Americans who save money in a bank.

Think of Rogers as a kind of American George Soros, with a mild Southern accent.

Not that Rogers is a clone of Mr. Soros's political views, but both are big-name investors who have been known to make bold bets on currencies and other assets that most people don't put in their brokerage accounts.

Actually, the two worked together at the Quantum Fund for years, before Rogers left to do his own thing (which included an epic globe-spanning motorcycle journey).

In recent years, Rogers has become well known in the investment world as a bull on commodities. He's especially optimistic about investments in farming. A growing world population is increasingly developing middle-class lifestyles -- putting more demand on the world's arable land.

Rogers has written books with titles such as "Hot Commodities" and "Investment Biker" and, in 2009, "A Gift to My Children: A Father's Lessons for Life and Investing."

His bet for the US dollar is short term – and shows his contrarian instincts. He said Friday that with 97 percent of investors saying they're bearish about the dollar (including him), he had to buy in.

Similarly, he's gone short against emerging-market nations.

In part, the dollar has been rising lately because a key alternative, the euro, is mired in concerns about a sovereign debt crisis in nations like Greece. But Rogers said eventually creditors will stop wanting to loan money to the US government.

"Take a chain saw to spendng in the United States," he advised. "We're not in charge of our destiny, we're the largest debtor nation in the world."