Prediction Markets Weekly Digest: May 25 to 31

Three markets, one big story. Iran’s airspace by May 31 is a coin flip, last week looked like a sure yes before Iran walked it back, and people who read the fine print made a fortune shorting the spike. The LA Mayor race is June 2: Bass wins, but Spencer Pratt is favored for second, which forces a November runoff. The NBA Western Finals are tied, with Wembanyama as the swing. And on the business side: a soldier allegedly traded on classified intel, Congress wants Kalshi and Polymarket to testify, and Kalshi raised a billion dollars the same week the letters arrived.

Trending markets resolving this week

POLITICS

Iran Closes Its Airspace by May 31

Last Thursday, there was a small window to act and most traders missed it.

An official notice went out saying Iran was restricting its airspace. Within minutes, the Polymarket bet on Iran closing its airspace shot up to near 100%. Then Iran’s Civil Aviation Authority clarified: the closure was only partial. Just the western area. None of the five airports the bet actually requires. The market crashed, then bounced back.

⚠️ Predictionist Tip: Any new official Iranian aviation statement, or escalation in US-Iran nuclear talks, can shift this market significantly overnight.  Read the resolution criteria, not just the news ticker.

POLITICS / ENTERTAINMENT

LA Mayoral Primary: Karen Bass vs. Spencer Pratt

Spencer Pratt is running for Mayor of Los Angeles. He’s a reality TV star, he lost his home in the Palisades fires, and he’s a Republican. That sentence alone says a lot about this race.

The primary is June 2. Bass is the heavy favorite. Pratt is well behind, but his number is climbing, and a Republican pulling real support in one of the most Democratic cities in the country says something. The anti-Bass vote is finding a face. Bass was in Ghana when the Palisades fires started. Her office later edited a report about the fires, and the person who wrote the original went public about it.

The better bet to watch is the second-place one. Pratt is the clear favorite there. To win Los Angeles outright, you need a majority. If Bass falls short, this race keeps going through November.

⚠️ Predictionist Tip: Final turnout data and any last-minute news about the fires report are the signals to watch before June 2. A Bass win below 55% keeps the runoff story alive.

SPORTS

NBA Western Conference Finals: OKC vs. San Antonio

Game 5 could flip this market. That’s the main thing to know going into the week.

Oklahoma City leads the series, but Victor Wembanyama’s Game 4 reminded everyone why San Antonio is still in it. The series is tied. One Spurs win and their odds jump before the weekend.

Here’s why this market is worth watching even if you don’t follow basketball: it moves after every game. A fresh read on the series every two days. For traders, that’s a new chance to jump in each time.

Wembanyama is what makes this hard to call. When he’s on, San Antonio can beat anyone..

⚠️ Predictionist Tip: Check injury reports before tip-off each night. Foul trouble on Wembanyama changes games faster than anything else in this series.

Whale moves and big plays

Unknown whales – Polymarket – Iran closes its airspace by May 31

Coming back to that Iran market spike, when the airspace notice hit on May 23, big money piled in above 95 cents, paying near-certain prices on what looked like confirmed news. The thinking made sense at the time: official filing, aviation trackers confirming, no pushback yet.

But they got the bet wrong. The contract needs at least two of five named airports to close. The notice only covered one region. Iran pushed back within the hour. Traders who saw that denial first and knew what the bet actually required shorted from 99 cents down to the 20s. Up to 70x gain in minutes.

⚠️ The lesson is not “don’t trade Iran markets.” It is “read the full resolution criteria before the chart.”

Prediction market industry news

The Polymarket trade that ended up in a congressional hearing

A US soldier named Gannon Van Dyke allegedly used classified military intel to bet that Maduro would be out of power in Venezuela. He placed the bets in late December, knowing a secret US operation to capture Maduro was coming. Maduro was captured on January 3. Van Dyke turned about $33,000 into more than $400,000. He’s now been charged. The House Oversight Committee responded by sending formal letters to Kalshi and Polymarket, demanding testimony by June 5. The committee chair has hinted at new laws that would ban government workers from trading on prediction markets at all. Kalshi launched a lobbying arm the same day the letters showed up.

Kalshi raises $1 billion

Kalshi just closed a big funding round, valuing the company at $22 billion, double what it was worth five months ago. Coatue led the round, with Sequoia, a16z, and others joining in. The number that says it all: institutional trading on the platform is up 800% in six months – a clear sign that prediction markets are booming. Full announcement.

NHL joins the regulatory framework for sports prediction markets

The NHL is now the second major US sports league to formally team up with the CFTC – the federal agency that regulates event contracts – on how prediction market sports bets should work. Major League Baseball did the same earlier this year. Both leagues are getting ahead of the rules instead of waiting for a court fight to decide it for them.

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