Stock markets trade mixed amid introduction of new closing auction sessionSensex and Nifty traded mixed after the new Closing Auction Session for F&O stocks took effect. The Closing Auction Session (CAS) in the equity cash segment became operational on Monday, introducing a new auction-based mechanism for determining the closing prices of eligible stocks in a move aimed at making the price discovery process more transparent and robust. The 30-share BSE Sensex climbed 97 points to 78,736.20 in early trade. Benchmark equity indices Sensex and Nifty on Monday ended with an unusual aberration after stock exchanges introduced the new auction mechanism. “The 390-point spurt in the Nifty yesterday caused primarily by the new closing auction session (CAS) for determining the closing prices of stocks in the F&O segment is expected to normalise today.