METHODOLOGY · HOW EVERY INDEX IS BUILT

Many markets in, one reading out.

Every index follows the same four steps, and each published value can be traced back to the prices behind it.

~10.7MMARKETS READ
9EXCHANGES
HourlyRECALCULATED
THE RAW MATERIAL · ONE CONTRACT, ONE PRICE
$0.7373%

An example contract: the traded price is the chance the market is pricing in.

01Market selection
AI finds the markets relevant to each index, using criteria set in advance.
02Classification
Is it about the theme? Does a higher price move the index up or down? How much should it count?
03Weighted aggregation
More money behind a market, more weight. Seat counts are the exception: one seat is one seat.
04Traceability
Every value traces back to the markets, the prices at that hour, and how each was classified.
Sources: ForecastEx · Gemini · IBKR · Kalshi · Manifold ◦ · Metaculus ◦ · Polymarket · PredictIt · Robinhood. ◦ = play money, shown but not weighted.
THE RESEARCH

More exchanges, better forecasts

Each exchange is a crowd putting money behind its best guess. A well-weighted blend of exchange prices beats any single exchange most of the time.

87 of 100

simulated scenarios where the blend beat the best single exchange

5 of 5

exchanges outperformed on 3,000 questions, 2.4% lower error than the strongest

01 · ERRORS CANCEL OUT

Each exchange misses in its own way. Blended, the misses partly cancel (Bates and Granger, 1969).

02 · TRACK RECORD EARNS WEIGHT

Exchanges that called past questions well count for more; consistently biased ones count for less.

03 · THE DOWNSIDE IS CAPPED

Weights lean toward an even split, so a short track record can’t chase noise.

Results come from a simulation of five exchanges of similar quality, not from Micah’s index data, scored by Brier score. Today’s published indexes weight by money (step 03); weighting by track record is where the research points next. It can’t remove an error every exchange shares, such as an ambiguous resolution rule.

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The full paper, with the derivation, simulation design and a worked example.

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