The disconnect between global markets and bond yields is something Mark Grant, chief fixed income strategist at Hilltop Securities, says he hasn't seen in four decades. The dip in global bond yields, though, is herding global investors to the U.S.
"People are going anywhere they can to try and get a return on their capital," Grant told CNBC's "Squawk Box" on Tuesday. "That money's going to come to the United States, where it's certainly much safer where we're not in as bad a financial condition."
Money moves in and out of Asia, and Europe, depending on the best opportunity, he said. The U.S. is now getting a "spillover" effect" as other major central banks kick up quantitative easing and go to negative interest rates.
"Clearly the best opportunity now for yield is in the U.S.," Grant said. "You're seeing huge amounts of money coming into the United States and I think that's what's driving these markets."
The S&P 500 closed at an all-time high Monday, and the Dow hit a high for the year. Meanwhile, U.S. bonds hit record lows last week, with the U.S. 10-year Treasury note closed below 1.4 percent for the first time in history.
"The disconnect, is quite frankly, unreal," he said.
Grant said there's no fundamental or technical analysis, the only rational reason is the world's central banks.
"America is the last man standing with positive yields and it will not be until Treasury yields approach European and Japanese sovereign yields that this migration of money into American securities will end," he said. "Normalcy is just not present and won't be for years, in my opinion."
He pointed to fear in European markets like Italy, with low economic growth and struggling banks. The euro zone, as a result of the United Kingdom's decision to leave the European Union, is also in "significant" trouble, Grant said. While the euro won't disappear, he said any further breakup of the EU calls its question into value.
"The U.S. is looking like a safe place for both equity and debt and of course our yields in the United States for Treasurys and corporates are significantly higher than what you can find in Asia and Europe," Grant said.
It's not just fixed income. The "barges have sailed off from Asia and Europe" as they go to negative rates, bringing massive amounts of money to the U.S. both in equities, debt, risk-on and risk-off assets. U.S. stocks have become increasingly appealing, especially those that kick off higher dividend yields than yields in Treasurys.
"They're safer than I'd though," Grant said.