Corteva (CTVA) will replace Olin Corp (OLN) in the S&P MidCap 400 prior to the opening of trading on Oct. 6, S&P Dow Jones Indices said Thursday.

S&P said Vylor (VYLR ) was added to the S&P 500 on Oct. 1 when S&P 500 constituent Corteva spun off Vylor in a deal completed on that date. It said Vylor replaces Corteva in the S&P 500.