The yield curve—with one exception in 1966—has basically predicted every recession according to Natixis Chief Economist Joseph LaVorgna. If the curve inverts on October, 2018 then history would say a recession would occur between August 2019 and August 2020.

"Now it's possible that this time is different and the curve might be sending a different signal because long rates are relatively low," LaVorgna added.

In July, the U.S. economic growth rate hit 4.1 percent for the second quarter, its fastest pace in four years. And the stock market has set a record for the longest bull market in U.S. history.