Belief Systems constructs rules-based indices from market-implied probabilities in prediction markets. The point-in-time record is free for non-commercial academic use.
Researchers remain fully independent. No compensation, advisory title, or endorsement request.
Public files cover the index record. Research access extends that record to the constituent level.
Include your name, institution, and a brief description of the research question.
Every file is designed to preserve what was known, held, and computed at the time.
Each observation records the composition and methodology versions in force; the composition version joins to constituent target weights.
Resolved and removed markets remain in the historical record at their as-published values.
Rule changes receive a new version and apply prospectively to subsequent observations.
Permanent snapshots and delivered flat files keep a research sample reproducible over time.
We welcome independent use and direct criticism of the index construction.
Which weighting schemes best transform constituent probabilities into a stable belief measure?
When do event-risk indices lead, lag, or add information to survey measures?
What are the return, volatility, and correlation properties of event-risk indices?
How do aggregate indices perform against polls, models, and expert forecasts?
Dated archive URLs resolve to the exact files in each published snapshot.
Data provided by Belief Systems (beliefsystems.xyz).Belief Systems (2026). Belief Index Data, snapshot [YYYY-MM-DD] [data set]. Retrieved from https://beliefsystems.xyz/data/archive/[YYYY-MM-DD]/Machine-readable citation metadata (CITATION.cff) ships with every bundle. Tell us when the data appears in a paper so we can follow the work.
Browse the archive →For constituent detail or a custom extract, send your name, institution, and a brief description of the intended research. No form is required.
Free for non-commercial academic research. Commercial data and methodology use is available through Index Services.