Prediction markets should not rely on evidence that becomes available after a market's deadline because doing so undermines finality, creates information asymmetry, and introduces uncertainty into what traders are actually betting on.
The purpose of a Market Deadline
The purpose of a market deadline is to establish a fixed point in time at which the outcome can be determined. If evidence published after the deadline can be used to change the result, then the deadline loses much of its meaning. Participants need to know that once the clock reaches 11:59 PM ET, the universe of admissible evidence is effectively closed.
The problem of hindsight resolution
A key problem with allowing post-deadline evidence is that it creates hindsight resolution. Traders are forced to wait indefinitely for future disclosures that may or may not emerge. A market that appears unresolved at the deadline can suddenly flip days, weeks, or even months later because new information is released. This is inconsistent with the principle that prediction markets should provide clear and timely outcomes.
The MicroStrategy example
In the case of MicroStrategy, the company announced on June 1 that it had sold 32 BTC during May. While that announcement may suggest that sales occurred before May 31, the market participants had no way to verify this before the deadline. At 11:59 PM ET on May 31, there was no publicly available evidence establishing that a sale had occurred.
The Risks
Prediction markets generally operate on publicly available information, not undisclosed corporate records. If resolutions can depend on facts that were unknowable at the deadline, traders are effectively betting on hidden information rather than observable reality. This creates an unfair environment where outcomes depend on future disclosures rather than what could be reasonably verified during the life of the market.
There is also a significant manipulation concern. If post-deadline evidence is admissible, companies, governments, or individuals can influence market outcomes by choosing when to release information. An event could allegedly occur before the deadline, but proof might not emerge until much later. The longer the gap between the deadline and the evidence, the greater the potential for disputes, ambiguity, and selective disclosure.
Consistency
Another practical issue is consistency. Once post-deadline evidence is allowed, it becomes difficult to define limits. Should evidence released one day later count? One week later? Six months later? One year later? Without a clear cutoff, markets can remain vulnerable to endless revisions as new information emerges.
Why Clear rules matter
Markets require objective and predictable standards. A simple rule that only evidence available before the deadline may be considered is easy to understand and apply. Everyone knows what information counts, disputes are minimized, and traders can assess risk using the same set of facts.
Most importantly, prediction markets are not courts conducting historical investigations. Their purpose is to settle tradable contracts efficiently and consistently. Courts may spend years uncovering facts about past events, but prediction markets need clear rules that can be applied quickly and uniformly. Excluding post-deadline evidence prioritizes certainty, finality, and equal access to information over retrospective fact-finding.
Polymarket precedent
This is how Polymarkets have been resolving for years. There's a clear cut-off time at the market deadline.
A recent example would be a market about Trump holding a phone call with Mark Rutte. In the whole month there was just one vague statement by Rutte saying they "had a conversation". Traders argued this was enough, but it got disputed. While the dispute process was going on, FT and other websites published confirmation of this phone call. But it was published 1 day after the market contract ended. It correctly resolved to NO under the market rules, even though the event happened.
A dispute is not an extension of the deadline
A dispute process is not a mechanism for extending a market's deadline. The purpose of a dispute is to review whether the proposed resolution correctly reflects the state of the world as of the market's stated cutoff time. If evidence that emerges during the 24–48 hour dispute window can be used to determine the outcome, then the market's effective deadline becomes the end of the dispute period rather than the stated deadline. This would create a moving target where traders are no longer predicting what happens by 11:59 PM ET, but what evidence might emerge before UMA voting concludes. The clock stops at the market deadline, not when the dispute process ends. The dispute window exists to evaluate the correctness of a resolution based on facts available before the deadline, not to allow new post-deadline events or disclosures to become outcome-determinative.
Conclusion
The June 1 announcement by MicroStrategy would be irrelevant to a market closing at 11:59 PM ET on May 31. Regardless of what the announcement claimed about prior activity, the evidence itself did not exist before the deadline. Therefore, it should not be considered when determining the market outcome.
I wrote this article to help (new) traders understand why there's a hard cut-off at 11:59 PM. New traders might not know this and Polymarket does not always do a great job of communicating that. I hope this article helps those that did not understand Polymarket's clarification. If you have any questions, feel free to comment.
