Guides7 min read

How to Find Prediction Markets Worth Trading: Liquidity, Spread, and Open Interest

Learn how to screen prediction markets using liquidity, bid–ask spread, open interest, volume, expiry, and executable price—then verify the contract before placing a trade.

A market can be interesting without being tradable. Viral attention, high volume, or dramatic odds do not guarantee a reasonable entry and exit. A useful discovery process starts with the question, then screens liquidity, spread, open interest, expiry, market age, and current executable depth. Hunch Markets and Discovery help narrow the universe; the event ticket decides whether the selected order is actually workable.

The four metrics traders confuse most often

MetricWhat it measuresWhat it does not prove
VolumeHistorical traded value over a periodCurrent depth or ability to exit
LiquidityAvailable ability to trade near current pricesContract quality or correct probability
Open interestOutstanding exposure that has not been closed or settledShares offered at the current bid or ask
SpreadDifference between best bid and best askDepth beyond the best price

Swipe to view all columns →

Product behavior and market state can change; verify the live interface before acting.

Use them together. A market can have high lifetime volume but a wide current spread, or large open interest with little immediate exit liquidity.

Start with a question you can evaluate

Do not begin with a leaderboard and assume the top market is the best opportunity. Begin with an event whose rule and evidence you can understand.

Before screening execution, ask:

  • What exactly resolves YES?
  • Which source decides?
  • When does the market stop counting evidence?
  • What information could change the probability?
  • Why might the current crowd be wrong?

If you cannot explain the contract in one sentence, more liquidity only makes it easier to trade something you do not understand.

Use Hunch Markets for structured screening

The current Hunch Markets implementation includes search, venue selection, category controls, favorites, and sorts such as trend, momentum, volume, liquidity, open interest, 24-hour change, expiry, and market age. Screening controls can include volume, probability range, end date, market age, and spread.

Hunch Markets lets you compare and sort live markets by signals such as volume, liquidity, open interest, price movement, expiry, and market age. Live data changes; verify the current interface before acting.

Each sort answers a different question:

Sort or filterReader job
TrendingFind current attention and activity
MomentumFind acceleration rather than total scale
VolumeFind heavily traded markets
LiquidityFind markets with more executable capacity
Open interestFind larger outstanding exposure
24-hour changeFind rapid probability movement
ExpiryFind near- or long-dated contracts
Market ageFind newly listed or established markets
SpreadAvoid markets with poor top-of-book pricing

Swipe to view all columns →

Product behavior and market state can change; verify the live interface before acting.

No sort is a quality score. It is a way to reduce the search space.

Use Discovery to explore topics, not tickers

Hunch Discovery clusters markets into themes and lets the reader move from broad topics toward individual events. The production surface can size or rank groups using market count, liquidity, open interest, or 24-hour volume.

That is useful when you know the topic—macro, elections, crypto, sports—but not the exact contract.

Discovery is not a forecast engine. A large visual cluster means the chosen metric is large, not that its markets are mispriced.

Screen liquidity before probability

A 30% probability can look attractive, but a trader buys at the ask and sells at the bid. Inspect:

  • best ask for the intended buy;
  • best bid for a possible exit;
  • shares available at both;
  • average price for the intended amount;
  • depth one or two levels away;
  • whether an AMM quote has material price impact.

Liquidity is amount-specific. A market can be liquid for a $20 trade and illiquid for a $2,000 trade.

Calculate the spread

spread = best ask − best bid

If the best bid is 47 cents and the best ask is 51 cents, the spread is four cents. Buying and immediately selling one share would lose roughly that spread before fees and movement.

You can also express spread relative to the midpoint, but the absolute cents often communicate prediction-market cost more clearly.

Spread can widen when:

  • news creates uncertainty;
  • market makers reduce risk;
  • expiry approaches;
  • the market is thin;
  • one side of the book is consumed.

Interpret volume correctly

Volume answers “how much traded?” It can identify attention and historical activity. It does not tell you:

  • whether current bids and asks are tight;
  • whether volume came from one burst;
  • whether the same accounts traded repeatedly;
  • whether an exit is available now;
  • whether the contract is well designed.

Compare recent volume with current liquidity. A market with huge past volume and an empty book should not pass an execution screen.

Interpret open interest correctly

Open interest represents outstanding positions or exposure under the venue’s methodology. It can show that capital remains committed to the market.

It is not an order book. A holder does not become an available seller until an order is placed.

High open interest plus low liquidity can mean many positions exist but are difficult to transfer at a fair price. That matters for exits and for the reliability of an amount-specific quote.

Add expiry and market age

Near-expiry markets can react quickly and lose liquidity after decisive information arrives. Long-dated markets can lock capital and remain sensitive to rule interpretation.

New markets can offer early information discovery but often have:

  • wider spreads;
  • lower depth;
  • fewer informed participants;
  • unresolved rule questions.

Established markets can be easier to execute but more crowded. Use age as context, not as an automatic opportunity signal.

Compare venues when a match exists

If Hunch shows a similar market on another venue, compare:

  • exact rules and deadline;
  • executable ask or bid;
  • liquidity and amount-specific average;
  • market type and order support;
  • fees;
  • collateral and account readiness.

A different price can reflect a different contract or stale book. It becomes useful only after the reason is understood.

Treat Quick Buy as a shortcut, not research

Quick Buy reduces interaction cost after the market has been reviewed. It should not replace:

  • reading the contract;
  • selecting the correct outcome;
  • checking the venue;
  • inspecting execution price and amount;
  • confirming risk.

The first use of a market should go through the full event and review workflow. Any future shortcut should still expose an authoritative final confirmation.

A repeatable market screen

1. Define the topic and thesis

Write the event and evidence you understand.

2. Use Markets or Discovery

Search directly or explore a topic cluster.

3. Apply tradability filters

Set minimum liquidity or volume, acceptable spread, expiry, market age, and venue.

4. Open the exact event

Read the full rule and resolution source.

5. Test your actual amount

Enter the intended size without submitting. Record average price, shares, fee, spread, and available balance.

6. Plan the exit

Check the current bid, depth, expiry, and whether limit orders are supported.

7. Compare the thesis with the price

Only now decide whether the market is worth trading.

Common false positives

  • High volume with a wide current spread.
  • Large open interest with weak exit liquidity.
  • Rapid 24-hour change after the relevant news is already priced.
  • A new market with attractive odds but ambiguous rules.
  • A “cheap” one-cent share with almost no realistic path to settlement.
  • A cross-venue difference caused by mismatched deadlines.
  • A Quick Buy preset that is too large for visible depth.

Frequently asked questions

What is the most important metric for a prediction market?
There is no single metric. Contract clarity comes first; liquidity, spread, depth, open interest, volume, and expiry answer different execution questions.
Is high volume the same as high liquidity?
No. Volume is historical trading; liquidity is the current ability to transact near an expected price.
Does high open interest make a market easy to exit?
No. Holders must place orders, and the current bid side still determines executable exit liquidity.
What is a good spread?
It depends on price, size, time horizon, and expected edge. Compare the spread with the advantage you believe exists and include fees and depth.
Should I trade trending markets?
Trending is a discovery signal, not a recommendation. Verify that the relevant news is not already reflected in the executable price.