Shenzhen Stock Exchange to cap ChiNext index single-stock weight at 15%

This is a structural, not a directional, change: the exchange is pre-committing to a glide path that dilutes any single dominant name in ChiNext rather than letting concentration build unchecked. The ratchet — caps only lowered, never raised, until the top weight sits at or below 14.5% — matters more than the headline 15% figure, because it removes the option of passively tolerating renewed concentration between reviews. Index-tracking products benchmarked to ChiNext will face incremental rebalancing toward smaller constituents over time, though the effect is spread across multiple reviews given the 2026 effective date. The open question is how much of that dilution is absorbed by passive flows versus offset by active positioning.