The spread between three-month and 10-year US Treasury yields has inverted for the first time since 2007.

Such inversions on a different part of the so-called yield curve have preceded all nine US recessions since 1955.

The Dow Jones Industrial Average t umbled 400 points as Friday's yield-curve inversion sparked growth concerns.

A keenly watched measure of market sentiment on recession has just indicated that recession is increasingly in the cards.

Ten-year Treasury yields, which were already at a one-year low, declined further Friday, pushing them below the three-month yield. Bloomberg said the so-called inversion on this part of the yield curve is the first since 2007, suggesting credit markets are fearful of US growth declining.

The S&P 500, Nasdaq composite, and Dow Jones Industrial Average all fell more than 1.2% as investors digested the news that a portion of the yield curve had inverted, economist Ed Yardeni, the president of Yardeni Research, told Markets Insider.

It follows a Federal Reserve decision not to hike interest rates on Wednesday, highlighting the possibility of slower US growth in the coming year and forecasting just one hike through 2021.

A flat or negative yield curve suggests investors believe keeping your money in short-term bonds is more uncertain than bonds that pay off much later. If the long-term horizon looks riskier than the short-term one, it's a sign something's amiss in the economy.

The same happened with three- and five-year spreads for the first time in 11 years in December. Concerns about global growth slowing and higher interest rates, along with simmering trade-war tensions, are thought to be behind the inversions.

The yield curve inverted between the two- and 10-year yield before the recessions of 1981, 1991, 2000, and 2008. An inversion on that part of the yield curve has preceded all nine US recessions since 1955.

Whether that means a recession is likely in the next few years depends on numerous factors, but it's a stark sign of things to come from a usually emphatic bellwether.

Rebecca Ungarino contributed to this report.