The U.S. economy is firing on all cylinders, yet 75 percent of ultra-high net worth investors predict it will hit recession by 2020, a J.P. Morgan survey found. Of those expecting an economic downturn in the U.S., a fifth of respondents — 21 percent — believe it will begin in 2019 and 50 percent expect the next recession to start in 2020. J.P. Morgan Private Bank's Spring Investment Barometer, released this week, surveyed more than 700 global private clients across Europe and the Middle East. Ultra-high net worth individuals (HNWI) are generally classified as anyone with more than $30 million in liquid financial assets, and high-net worth is defined as having more than $1 million. The ominous predictions may come as a surprise to some, seeing as the U.S. is enjoying strong growth, robust corporate earnings and its lowest unemployment in 17 years. The International Monetary Fund recently upped its U.S. growth forecast for 2018 to 2.9 percent. J.P. Morgan's Anthony Collard, head of U.K. and Nordic investments, said that while concern was evident among ultra-high net worth investors regarding America's economic future, the bank does not see signs of it being close to a recession. "Until we see clear imbalances building, and policy approaching a point where it really constrains economic activity, we lean towards a view that the cycle will continue to expand," he said.

But there is debate among economists as to whether this growth — fueled by a synchornized global upswing and stimulus injections like the recent Tax Cuts and Jobs Act, which slashed corporate taxes, and an enlarged federal spending package — will last beyond 2019. Economists like Carl Tannenbaum at the Chicago-based Northern Trust warn that growth will not keep pace with the U.S. budget deficit, which is set to top $1 trillion in the next two years. "Sometime in the next decade we're going to have a recession which is really going to throw us off that trajectory," he told CNBC this week. And billionaire Microsoft founder Bill Gates makes a similar prediction, though without a specific timeline. Asked in March if there would be another financial crisis like the one in 2008, Gates replied, "Yes. It is hard to say when but this is a certainty." Market observers also worry about the flattening of the yield curve. The short-term U.S. two-year Treasury yield is nearing that of the 10-year yield, rising to its highest level since 2008 this week. This typically triggers worries that a recession is on the horizon, since higher short-term yields suggest that inflation and interest rates are expected to remain low for a longer period.