Jeffrey Gundlach, CEO of DoubleLine, is watching the Treasury yield curve as a primary harbinger of recession – and he warns that a downturn is almost assured if it inverts past a certain level. A yield-curve inversion occurs when yields on short-term U.S. Treasury bonds are higher than those of longer-term Treasurys. Bond yields move inversely to prices. "I'm waiting for the 2s/10s to invert by 50 [basis points]," Gundlach told CNBC in an interview on the sidelines of the Future Proof wealth conference in Huntington Beach, Calif., referring to yields on U.S. 2-year Treasury bonds and 10-year Treasurys. "5s/30s finally reinverted again," Gundlach added, referring to 5-year and 30-year Treasury bonds. "That might get to like 25 [basis points]." "I think at that level, it's almost assuredly on the edge of a coming recession," he said. While both of those respective parts of the yield curve are inverted, they haven't yet reached Gundlach's stated thresholds. The 2-year and 10-year spread was inverted by about 37 basis points (or 0.37%) as of 1:33 p.m. ET on Wednesday. The spread between the 5-year and 30-year was about 11 basis points (or 0.11%). Bond yields had climbed on Tuesday as stocks sold off sharply after a hotter-than-expected inflation report . Spreads on Treasury yields narrowed. On Wednesday, even as stocks recovered, the yield on the 2-year Treasury — the part of the curve that's most sensitive to the Federal Reserve's policy — was still higher than those of the 5-, 10-, and 30-year notes. Gundlach is watching for a "massive sell-off at the short end [of the yield curve] and the long end doing almost nothing. That's a real sign that you're getting very late, late cycle." He called the yield curve "the granddaddy" of recession indicators, during a Q & A with CNBC's Scott Wapner. "I think the chance of recession in 2023 is really quite high," Gundlach told Wapner.