On Polymarket, the contract on a Tesla-SpaceX merger announcement in 2026 moved first, hitting 23.5 cents within about 45 minutes of the first reports, then fell back to 18.5 cents. The 2027 contract rose later in the evening, peaked at 71.5 cents and still stood at 68 cents early Wednesday.
Prediction-market traders reacted quickly to Elon Musk's disclosure that Tesla and SpaceX have formed committees to discuss a merger. What they kept by morning says more than what they bought in the first hour.
SpaceX's earnings call began at 4:30 p.m. Eastern on Tuesday, and the first reports of Musk's remarks appeared at about 5:27 p.m. On Polymarket, the contract that pays $1 if a merger is officially announced by Dec. 31, 2026, moved first. It rose from 18.5 cents to 21 cents by 5:30 p.m. and reached 23.5 cents between 6:10 and 6:40 p.m. By 6:50 p.m. it was back at 18.5 cents, and it touched a low of 17.5 cents between 9 and 10 p.m. before rising overnight to 22 cents at 4:47 a.m. on Wednesday. No new headline was identified to explain the overnight rise.
The contract for an announcement by Dec. 31, 2027, held between 65.5 and 67 cents through the first hour after the reports. It ticked up to 67.5 cents at 6:30 p.m., reached 70 cents at 6:40 p.m. and peaked at 71.5 cents at about 7:10 p.m. It stood at 68 cents at 4:47 a.m., about 2 points above where it started.
What survived the evening
The two contracts ended in similar places relative to their starting points, but by different routes. The near-dated bet spiked and fully reversed within about an hour, then drifted back up overnight on no identified news. The long-dated bet moved later, held most of its gain and gave back only part of it by morning.
That pattern fits what Musk said. He confirmed a formal process, but also said the committees "have not reached agreement on the terms of any transaction," that treating a deal as certain "would be overstating it" and that Tesla approval would require a majority of all outstanding shares. A trader who believed him had more reason to keep a higher price on an eventual deal than on one within 10 weeks.
Kalshi's different test
Kalshi's contracts are worded differently. They resolve on an official announcement of a definitive, binding agreement for a combination of the two companies, a higher bar than Polymarket's official announcement, so the two sets of prices are not directly comparable.
Kalshi's prices were mixed against the previous prices its system reports, whose reference time is not stated. The contract on a deal before Jan. 1, 2027, last traded at 18 cents, against a previous price of 14 cents. The May 1, 2027, contract was at 61 cents, against 57 cents, and the contract on a deal before 2028 was unchanged at 77 cents. The March 1, 2027, contract was at 42 cents early Wednesday against a previous 49 cents, and later traded at 46 cents, which suggests at least some of the apparent decline reflected stale quotes in a thin market.
A small market
These books are thin. As of early Wednesday, the Polymarket 2026 contract had about $35,400 of liquidity and about $9,400 of trading in the previous 24 hours. Kalshi's strikes traded a few thousand contracts each. Small orders can move prices several cents, so the direction of the moves matters more than the exact levels.
The stock market gave a parallel signal. Tesla was indicated about 1.6% higher at about 5:40 a.m. Eastern. SpaceX was indicated about 9% higher, a move that also reflected quarterly results that beat forecasts.
Market implications
One reading is that traders are pricing a real process on a realistic timeline. The near-term spike faded quickly, while the contract that allows more than a year for an announcement kept most of its gain.
A second reading is that the near-term price is speculative. The 2026 contract climbed overnight without news, in a market where a few thousand dollars can move the price.
What to watch
Musk's comments on Tesla's earnings call after Wednesday's close; any filing naming committee advisers; trading volume in the 2026 contract; and Kalshi's March and May 2027 strikes. A statement on Tesla's call that rules out an announcement this year would test the 22-cent price directly.