The Supreme Court began last year examining the legality of the tariffs imposed by President Donald Trump on imported goods from nearly every corner of the world. The implications of the case are enormous — potentially reshaping the administration’s economic agenda, foreign policy, executive authority and even the cost of living for Americans.
The high court must determine whether the International Emergency Economic Powers Act, a 1977 law granting presidents authority to regulate international trade in response to a “threat” during a “national emergency,” applies to this case involving the tariff increases announced in April 2025.
If you want to get in on the action and make a prediction about the SCOTUS’s ruling on tariffs, Kalshi allows users in most of the 50 U.S. states to make predictions and win real money. We wrote a full explainer on how it works here and have a Kalshi promo code to help you get started.
Supreme Court Ruling on Trump’s Tariffs Odds
“Will the Supreme Court rule in favor of Trump’s tariffs? (Before 2028)” is the market with the highest contract volume related to this case. A ruling in favor of the president has shifted from a majority position to a minority one, with the probability of that outcome hovering near 27%.
The turning point in this market came Nov. 5, at the start of oral arguments. During the hearing, the justices expressed concern about a potential overreach by the White House into powers constitutionally reserved for Congress, which is responsible for setting federal tax and tariff policy.
Facing the strong possibility of an unfavorable ruling, Trump said after the hearing that he may need to “prepare a plan B” for his trade policy. That dynamic boosted contracts predicting a ruling against the tariffs, which now stand near a 73% probability.
Another Kalshi market focuses on how many justices will vote for Trump’s tariffs. The court’s 6-3 conservative majority has backed most major Trump policies since his return to power for a second term, including controversial measures on immigration, federal spending and independent agencies.
However, current market sentiment suggests this case may be an exception. The probability that all six conservative justices will support the president’s position is a minority view, with only about 8% of traders predicting that outcome.
The prevailing position is that three justices will vote in favor, with four or two votes also seen as relatively plausible outcomes. Contracts predicting that no justice will vote in favor exceed 10%, compared with less than 1% for scenarios in which seven or more justices back the policy — another sign of skepticism about a ruling favorable to the administration.
Another major question is when the court will issue its opinion on Trump’s tariffs. That question anchors a separate Kalshi market, where a minority of traders expect a decision in the near term.
Contracts predicting a ruling before Feb. 21 — the court’s next conference is scheduled for Feb. 20 — have fallen sharply in recent days. Positions forecasting a decision before March 1 have also declined, with most contracts now indicating that a ruling may take several more weeks.
For now, the justices have offered no signal that they are ready to release an opinion or that the case warrants an emergency decision, despite the significant implications. Several companies have already sought reimbursement of more than $100 billion in tariffs paid under the policy if the measure is ultimately overturned.
What is Kalshi?
Different than a traditional sportsbook and available in all 50 states, Kalshi allows users to make predictions across several unique markets, including sports, entertainment, elections and even weather.
Kalshi operates on a contract-based system where users buy "contracts" (priced between 1–99 cents) based on whether they believe a specific event will happen. The price of each contract fluctuates in real time based on market sentiment and like the stock market, traders can sell positions early to lock in profits (or minimize losses).
