August 2026 A-Shares Rebound Then Slump; Shanghai Composite Up 2.22%, ChiNext Falls 6.26%
Chinese A-shares staged a sharp rebound in early August 2026 before reversing course on August 19. The Shanghai Composite gained 4.56% between August 3 and 17, while the ChiNext rose 13.25%. On August 19, the ChiNext plunged 6.26% and the CSI 1000 fell 5.39%. Month-to-date gains were trimmed to 2.22% for the Shanghai Composite, 1.00% for the CSI 300, 5.17% for the ChiNext and 6.18% for the CSI 1000, down from 3.08%, 2.70%, 9.81% and 9.75% respectively on August 14. Trading concentration among the top 5% of stocks stood at 47.8%.
Between August 3 and August 17, 2026, the Shanghai Composite Index rebounded from 3,809 points to 3,983 points, a gain of 4.56%, while the ChiNext Index rose from 3,302 points to 3,740 points, up 13.25%. On August 19, the ChiNext fell 6.26% in a single session, dropping from 3,706 points to 3,473 points; the CSI 1000 declined 5.39% from 7,946 points to 7,518 points; and the Shanghai Composite fell from 3,990 points to 3,894 points.
As of the close on August 19, the Shanghai Composite was up 2.22% for the month, the CSI 300 up 1.00%, the ChiNext up 5.17% and the CSI 1000 up 6.18%. On August 14, these gains had stood at 3.08%, 2.70%, 9.81% and 9.75%, respectively.
Trading concentration among the top 5% of stocks by turnover reached 47.8% as of August 19. Historical data show that in November 2007, this metric fell back to 35% after breaking above 45%; in February 2018, it retreated to 35% from above 45%; and in February 2021, it fell to 42% after approaching 50%. In the current cycle, the July peak was 49.8%, and the August 19 reading of 47.8% represents a decline of two percentage points.