Start with the price
A prediction-market price tells us both where belief stands and how much uncertainty remains before the outcome is settled.
Introducing Belief Volatility
Probability tells you where belief stands.Belief Volatility tells you how far it may move.
Forward Belief Volatility (FBV) brings a forward-looking measure of movement to prediction markets – quoted in probability points over a clear period such as the next 30 days.
Two numbers · two questionsILLUSTRATIVE
Probability today
46%
Where belief stands.
0%100%
Belief Volatility (FBV) · 30 days
12points
How much it may move.
Movement can arrive through many paths, in either direction.
The missing number
A probability is a snapshot. Risk unfolds through time.
A market can sit quietly for weeks, then reprice when an election, ruling, or policy decision arrives.
Looking backward can make that market appear calm at exactly the moment the most important movement lies ahead. Belief Volatility is designed to look through the front window instead of the rear-view mirror.
The forward windowTIME →
Today30-day windowKnown event
A reading can rise as a known event enters the next 30 days – even when today’s probability has barely changed. The calendar changed what lies ahead.
How it works
Built from three simple ideas.
Place it on the calendar
Known event dates and the behavior of comparable resolved markets help estimate when that uncertainty may turn into movement.
Quote the movement
Belief Volatility turns the result into probability points over a stated period, making readings easier to compare across events and time.
Belief Volatility is a standardized estimate of how much prediction-market probabilities are expected to move over a stated horizon. The market price anchors the amount remaining; the timing within shorter windows is an estimate based on published rules.
How to read Belief Volatility
Movement, not destination.
12probability points
An illustrative FBV-30 reading of 12 estimates about 12 points of overall probability movement during the next 30 days.
It does tell youhow much movement is estimated and over what period.
It does not tell youwhich direction the market will move or where it will finish.
A familiar question
The forward-risk lens, applied to belief.
Measure
Starts with
Answers
Market probability
Starts withEvent-contract prices
AnswersWhat does the market believe now?
VIX
Starts withS&P 500 option prices
AnswersHow much might the stock market move?
Belief Volatility (FBV)
Starts withPrediction-market prices and event timing
AnswersHow much might belief move?
Who it is for
A common language for event-driven movement.
01Risk & strategy
See when event risk is moving closer.
Track how much repricing may enter the next month as elections, policy decisions, and other known events approach.
02Macro & political research
Compare events on one common scale.
Separate a market’s current probability from its potential to move, then compare that movement across questions and time.
03Prediction-market professionals
Add a forward view to the dashboard.
Use a consistent benchmark for expected probability movement alongside prices, liquidity, and recent trading activity.
MIDVOLSchematic – not live data
Five balance-of-power outcomes · one movement index
See it in practice
Midterms Uncertainty Index
MIDVOL is the first live Belief Volatility index. It measures estimated 30-day movement across all five possible U.S. midterm balance-of-power outcomes – not the fortunes of any one party or contract.
View the live indexQuestions, answered
The essentials.
How is Belief Volatility different from a probability?
A probability tells you where the market stands now. Belief Volatility estimates how much that probability may move during a chosen period. One measures level; the other measures movement.
Does a high reading predict which way a market will move?
No. Belief Volatility is non-directional. A high reading means more movement is estimated, not that the probability is more likely to rise or fall.
Is high belief volatility good or bad?
Neither. It describes the amount of possible repricing, not the desirability of an outcome. The same reading can matter differently to different portfolios.
How is Belief Volatility different from VIX?
Both answer a forward-looking question about movement. VIX reads prices from S&P 500 options. Belief Volatility starts with prediction-market prices and estimates when the remaining uncertainty may be resolved. The measures use different markets, methods, and units.
Why focus on 30 days?
Thirty days is long enough to capture meaningful event risk and short enough to remain useful for current decisions. Belief Volatility can also be calculated for other stated horizons.
Can I invest in Belief Volatility?
No. Belief Volatility is benchmark data, not an investment product, security, or prediction-market contract.
Transparent by design
A new measure should be easy to question.
Every published Belief Volatility reading identifies its horizon, unit, inputs, and method version. The complete rules are public, and past readings are preserved as originally published.
Forward Belief Volatility (FBV)