#Definition
Close time (also called expiration or trading deadline) is the moment when a prediction market stops accepting new trades. After close time, all positions are frozen until the market resolves and settles. No buying, selling, or position adjustments are possible between close and resolution.
In prediction markets, close time marks the transition from active trading to waiting for the outcome. It's typically set just before the event occurs or when information would give traders an unfair advantage, such as moments before polls close in an election or before economic data is released.
#Why It Matters in Prediction Markets
Close time affects trading strategy, pricing dynamics, and risk management.
Information cutoff: Markets close before outcomes become known to prevent traders with early access from exploiting the opportunity. Spreads may widen as market makers reduce exposure.
Timezone awareness: Always check the timezone of the close time. Polymarket typically uses UTC, while Kalshi and PredictIt use Eastern Time (ET). A market closing at "12:00 PM" could mean very different things depending on the platform. Missing the close by an hour because of timezone confusion is a common error.
Locked capital: Between close and settlement, your capital is frozen. A market closing two weeks before resolution locks your funds for that period without the option to react to developments.
Exit window: If you want to exit before resolution, you must do so before close time. This creates urgency for traders reconsidering their positions.
#How It Works
#Timing Variations
Close time varies by market type and platform policy:
Before the event
Event: Presidential election (November 5, 8:00 PM ET)
Close: November 5, 6:00 PM ET
Gap: 2 hours before polls close
Reason: Prevents trading on exit poll leaks
At event start
Event: Football game kickoff (Sunday, 1:00 PM ET)
Close: Sunday, 1:00 PM ET
Gap: None
Reason: Outcome unknown until game concludes
After event, before data release
Event: June employment numbers
Close: First Friday of July, 8:29 AM ET
Data release: 8:30 AM ET
Gap: 1 minute
Reason: Allows trading on expectations until announcement
#Market Timeline
A typical prediction market lifecycle:
1. Market Creation ─── Trading begins
2. Trading Period ─── Days to months of activity
3. Close Time ─── Trading halts ⬅️
4. Event Occurs ─── Outcome determined
5. Resolution ─── Platform verifies outcome
6. Settlement ─── Payouts distributed
#Market Timeline Visual
#Numerical Example
A market on quarterly GDP growth:
Market opens: January 1
Close time: April 28, 8:29 AM ET
Data release: April 28, 8:30 AM ET
Resolution: April 28, 9:00 AM ET
Settlement: April 28, 10:00 AM ET
Capital locked from close to settlement: ~1.5 hours
Compare to a longer-dated market:
Market opens: January 1
Close time: December 15
Event: December 31
Resolution: January 5 (next year)
Settlement: January 6
Capital locked from close to settlement: ~22 days
#Examples
#Example 1: Election Market
A market on "Will Candidate X win the election?" closes at 7:00 PM on election day, one hour before polls close in the candidate's home state.
This prevents:
- Trading on leaked exit poll data
- Front-running of early state results
- Exploitation of information asymmetry
Traders must finalize positions based on pre-election-day information.
#Example 2: Economic Data Release
A market on "Will initial jobless claims exceed 250,000?" closes one minute before the Thursday 8:30 AM release.
Traders can position based on:
- Previous week's data
- Economic forecasts
- Related indicators
After 8:29 AM, no adjustments possible; even if you realize you misread your analysis.
#Example 3: Sports Betting
A market on "Will Team A beat Team B?" closes at game start.
If Team A's star player is announced injured two minutes before kickoff:
- Traders who saw the news can sell their Team A positions
- Traders who missed it cannot adjust
- The market may gap dramatically at close
#Example 4: Regulatory Deadline
A market on "Will the Fed raise rates at March meeting?" closes when the Fed begins its statement at 2:00 PM ET.
The statement's first words might reveal the decision before the close time processes, creating a race between information release and trading cutoff.
#Risks and Common Mistakes
Missing the close
The most basic error: intending to trade but forgetting the deadline. Unlike stock markets with regular hours, each prediction market has its own close time. Set reminders for positions you're monitoring.
Assuming you can exit later
Traders sometimes enter positions planning to "see how it develops" and exit before resolution. But close time might come before you're ready to decide, or liquidity might dry up as close approaches.
Ignoring close-to-resolution gap
A market closing December 15 for a December 31 event locks your capital for over two weeks. New information during this period cannot be acted upon. Factor this dead time into expected returns.
Late liquidity collapse
As close approaches, market makers often reduce their quotes or widen spreads. The price you could have gotten at 10:00 AM might not be available at 5:00 PM when close is at 6:00 PM.
Time zone confusion
Close times are usually specified in a particular time zone (often ET for US markets). Traders in different time zones sometimes miscalculate the local equivalent, missing their window.
#Practical Tips for Traders
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Note close times for all active positions: Add calendar reminders with buffer time for last-minute decisions
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Trade early if size matters: Liquidity often deteriorates approaching close. Execute larger positions well before the deadline
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Check recent close time patterns: Some platforms systematically close markets earlier than expected events. Understand the platform's typical behavior
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Factor lock-up period into returns: A 10% expected return over 6 months with 2 weeks of locked capital is less attractive than the same return with 1 day of lock-up
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Plan for close-time volatility: Final hours often see sharp price moves. Decide in advance whether you'll participate or stand aside
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Verify close time hasn't changed: Platforms occasionally adjust close times for operational reasons. Confirm before assuming the original schedule applies
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Set limit orders before close: If you want to exit at a specific price, place your order early rather than racing the clock
#Related Terms
#FAQ
#What happens if I have open orders at close time?
Open orders are typically canceled when the market closes. They won't fill after close time even if the price later reaches your level. Only filled positions remain for resolution.
#Can close time be extended or changed?
Yes, platforms sometimes adjust close times due to event delays, technical issues, or rule clarifications. This can benefit or harm traders depending on their positions. Always verify current close time before trading.
#What's the difference between close time and resolution?
Close time is when trading stops. Resolution is when the outcome is determined and verified. Settlement is when payouts are distributed. These can be minutes apart (data releases) or weeks apart (long-dated events).
#Why do some markets close long before the event?
Reasons include: preventing trading on leaked information, accommodating time zone differences, allowing resolution verification time, or platform operational requirements. Each market's close time reflects its specific circumstances.
#Can I cancel a position after close time?
No. Once close time passes, all positions are locked until settlement. You cannot cancel, hedge, or adjust your exposure regardless of new information or changed circumstances. The only exception is if the platform voids the entire market.