Yields on 10-year Treasuries on Tuesday fell below yields on three-month Treasury bills in what is the classic economist definition of an inverted yield curve, triggering more market speculation about the potential for a wider economic slowdown.

The yield curve is a chart plotting the yields of Treasuries of different maturities. It is rare for longer-dated yields to trade below short-term ones since lenders normally demand a higher premium for lending funds for longer periods.