France Financial Markets Authority study finds closing auction exceeds half of regulated market trading in French equities without structural liquidity deterioration

The France Financial Markets Authority has published an analysis of trading at the close in French equities between 2018 and 2025, finding a marked concentration of activity in the closing auction on the regulated market, particularly for large-cap stocks. On CAC 40 shares, the share of value executed in the closing auction rose from 36% to 53%, driven by both higher volumes at the close and lower trading during the continuous session. Despite that shift, the study did not identify structural deterioration in liquidity, volatility or price formation on the regulated market, except during exceptional periods of geopolitical or health-related stress. The analysis also finds that execution fragmentation, already well established during continuous trading, is now extending to the close. While the regulated market's closing auction still concentrates most closing activity, other venues increasingly offer execution at the closing price without participating directly in setting that price, meaning execution is fragmenting while price formation remains on the primary market. On a consolidated all-venues basis, closing trades represent about one-third of traded value in CAC 40 shares, so continuous trading remains the main execution phase overall. The study also shows distinct participant profiles by trading phase, with high-frequency traders remaining the main participants in continuous trading, banks accounting for most flows at the close, and high-frequency traders gradually increasing their presence in the closing auction.