See the forced trades before they’re announced.
Passive funds overtook active in early 2026, and around $13 trillion now tracks the S&P 500 alone. When a stock joins or leaves an index, those funds have to trade it at any price. ORTEX forecasts which stocks move in and out before the official announcement, every trading day before the open.
What each forecast carries
Additions, deletions and weight changes, produced by applying each index provider’s published rules to current constituent and candidate data.
From 0 to 0.99, summarizing how firmly the rules and current data point to the outcome. It settles to 1.0 once the change is verified. Higher scores reflect names clearly inside or outside the rule thresholds; lower scores flag borderline cases worth watching.
The shares and notional value index-tracking funds would need to buy or sell to stay aligned, expressed in shares and in days of average daily volume, so the potential market impact is clear.
Forecasts are delivered daily before the open, via CSV and API, and reconciled against the official changes on the effective date. Index rules are set and owned by the respective index providers; ORTEX predictions are estimates, not official index actions.
Built for desks that trade the rebalance.
Daily forecast files, five years of history for validation, and delivery over CSV or API. Talk to us about licensing it for your desk.
See also: Short Interest data, Stock Scores and the ORTEX API.