What Is a Series?
Think of a series as a focused, thematic index fund. Just as the S&P 500 is a basket of 500 stocks representing U.S. large-cap equities, a Belief Index series is a basket of prediction markets representing a specific category of event risk.| Component | Equity Index Fund | Belief Index Series |
|---|---|---|
| Underlying assets | Stocks | Prediction market outcome tokens |
| Selection criteria | Market cap, sector, liquidity | Theme relevance, liquidity, resolution clarity |
| Weighting | Market-cap or equal weight | Rules-based (typically equal weight) |
| Rebalancing | Periodic (quarterly, annually) | On market resolution |
| Valuation | Stock prices | Midpoint of bid/ask quotes |
| Maturity | Generally perpetual | Defined by event resolution dates |
Series Examples
| Series | Theme | Typical Markets | Directional Exposure |
|---|---|---|---|
| U.S. Monetary Policy Easing Expectations 2026 | Rate cut trajectory | Fed rate decisions, inflation prints, employment data | Markets that resolve favorably if rates decline |
| U.S. Presidential Election Republican Expectations 2028 | Republican electoral prospects | Candidate victories, party-level results, primary outcomes | Markets that resolve favorably under Republican scenarios |
| U.S. Macro Data 2026 | Economic data releases | GDP prints, unemployment figures, CPI targets | Markets tied to specific macro outcomes |
Naming Conventions
Each series follows a structured naming convention designed for institutional clarity: Canonical name format:Belief [Geographic Scope] [Risk Domain] [Directional Expectation] [Time Horizon] Index
| Component | Purpose | Example |
|---|---|---|
| Belief | Brand prefix | Always first |
| Geographic Scope | Jurisdiction of underlying events | U.S., Europe, Global |
| Risk Domain | What class of uncertainty is measured | Monetary Policy, Presidential Election, Macro Data |
| Directional Expectation | Which direction of outcomes is tracked | Easing Expectations, Republican Expectations |
| Time Horizon | Calendar year or period | 2026, 2028 |
| Index | Suffix | Always last |
Directional expectations are always framed as expectations, never as outcomes or guarantees. “Easing Expectations” describes which markets are tracked, not a prediction that rates will fall.
Composition
A series composition defines exactly which markets are included and how they contribute to the index:| Property | Description |
|---|---|
| Markets | The specific prediction markets included in the basket, identified by condition ID |
| Tracked outcome | Which side of each binary market is tracked (YES or NO) |
| Weight | The relative importance of each market in the index calculation |
Example: Equal-weighted series with 7 markets
Example: Equal-weighted series with 7 markets
A rates-themed series with 7 markets, each assigned a raw weight of 0.1429:
Sum of raw weights: 1.0003. After normalization: each weight = 0.14286; sum = 1.00000.Equal weighting means no single market dominates the index. A surprise in any one market affects approximately 14.3% of the total NAV.
| Market | Tracked Outcome | Raw Weight | Normalized Weight |
|---|---|---|---|
| Fed cuts 25bps by March | YES | 0.1429 | 0.14286 |
| CPI below 3% by June | YES | 0.1429 | 0.14286 |
| Unemployment above 4.5% | YES | 0.1429 | 0.14286 |
| Fed cuts 50bps by June | YES | 0.1429 | 0.14286 |
| Core PCE below 2.5% | YES | 0.1429 | 0.14286 |
| 10Y yield below 4% | YES | 0.1429 | 0.14286 |
| Recession declared by Q4 | YES | 0.1429 | 0.14286 |
Series Lifecycle
Each series progresses through defined states as its underlying markets evolve toward resolution:Active
All underlying markets are open and trading. NAV is computed at each window using live midpoint prices from the Polymarket order book. Investors can mint and redeem shares at each NAV window (subject to capacity and risk limits).
Partially Resolved
One or more markets have settled while others remain active. Resolved markets use their settlement price ($1 or $0) in the NAV computation. The series continues operating normally — investors can still mint and redeem.This is the most common state for a mature series, as individual events resolve on different timelines.
Resolution Mechanics
When an individual market in the series resolves:- If the tracked outcome won: the market’s contribution to NAV becomes $1.00 (maximum value)
- If the tracked outcome lost: the market’s contribution to NAV becomes $0.00 (zero value)
- The resolved market continues to contribute to NAV at its settlement price — it is not removed from the basket
Example: Impact of a market resolution
Example: Impact of a market resolution
Consider a 5-market equal-weighted series (each market has 20% weight) with a current Raw NAV of 0.60:
- Market A resolves: tracked outcome wins (price goes to $1.00 from $0.75)
- Effect: The Raw NAV increases by approximately 0.20 x ($1.00 - $0.75) = +0.05
- New approximate Raw NAV: 0.65
- Effect: The Raw NAV decreases by approximately 0.20 x $0.75 = -0.15
- New approximate Raw NAV: 0.45
How Markets Are Selected
Markets are selected for inclusion in a series based on four criteria:- Theme relevance — The market must directly relate to the series’ stated risk domain. A rate cut market belongs in a monetary policy series; an election market does not.
- Sufficient liquidity — The market should have enough order book depth to produce a reliable midprice signal. Very thinly traded markets can distort NAV through wide bid-ask spreads.
- Clear resolution criteria — The market must have unambiguous settlement rules. Markets with subjective or disputed resolution criteria are avoided because they introduce oracle risk.
- Appropriate time horizon — The market’s expected resolution date should fall within the series’ intended duration. A 2026 series should not include markets that resolve in 2030.
Market selection follows systematic, rules-based criteria — not discretionary judgment. The selection methodology is designed to be reproducible and auditable.