Bond investing guru Jeff Gundlach is short-term bearish on the U.S. dollar, citing the Fed's intent to keep rates near zero for years to come, he said during his "Just Markets" webcast Tuesday afternoon.In August of last year, Gundlach, who heads DoubleLine Capital, said he saw the U.S. dollar weakening in the long-term.U.S. dollar ETFs include [[UUP]], [[UDN]], [[USDU]].Don't expect foreign investors to buy Treasurys as the foreign share of purchases has been declining years, he said.With the decline in the dollar, commodities should have room to run, he said, suggesting that investors keep ~25% of their portfolios in real assets such as real estate or industrial commodities.Big commodity ETFs include [[DBC]], [[GSG]], [[DJP]], [[PDBC]].He's neutral on both bitcoin and gold; stepped to the sidelines on bitcoin when it hit $23K, saying he doesn't like worrying about whether he's going to lose $20K in an hour.Earlier, in a CNBC interview,