TL;DR

The ACX 2025 Prediction Contest results are out, it’s time for a writeup.

I ranked 48th this year. On the plus side, I managed not to get myself disqualified from prizes, so I will be receiving $71.02 in prizes shortly!

This one was an exciting round, I was in 4th position until the question about Argentina’s inflation resolved negative, to my prediction of 85%.

In this round, I wrote down some notes on each question when I was making the prediction, so after showing the raw data, I’ll be able to give some thoughts on questions that went unusually well or badly – but the notes still weren’t that great so my analysis is quite limited.

Data

Here’s my favourite chart again, showing all our predictions and updates. This time it’s even more complicated than last year because Randomator joined us too.

Plot of scores and updates

How to read this chart: There are three pieces of information layered on top of each other. First, a question is coloured red or green depending on whether it resolved negative or positive, respectively. Second, the final predictions we submitted to the contest in Jan 2025 are shown as x, +, and * markers. Third, the update we made from our initial prediction to the prediction we put down after discussing our models together is indicated through an arrow. The black line in the centre represents 50:50 odds.

Here are our updates, sorted by my update (μ=+0.001):

Plot of Brier score change for both of us. … and sorted by ErrorMargin’s update (μ=+0.008):

Plot of Brier score change for both of us. … and sorted by Randomator’s update (μ=+0.015):

Plot of Brier score change for both of us. And here are the Brier scores for the individual questions:

Plot of Brier scores for both of us.

Question Spotlight

30. Will Argentina’s year-over-year inflation be below 30% for December 2025? 85%

So unfortunately even though I did take notes here, my notes justified a position of 38%, which would have been excellent.

Then after discussion I yanked it upwards to 92%! And finally corrected down to 85%.

No idea what happened in that conversation.

16. Will the US government release additional Epstein documents in 2025? 21%

My notes say:

Trump doesn’t particularly seem to care. There is no evidence that there is a list waiting for release.

I think both of these are factually wrong, and were probably wrong at the time. This I put down to not caring enough about the question to research it properly.

27. Will Iran possess a nuclear weapon before 2026? 38% and 9. Will there be at least 1,000 deaths due to direct conflict between Israel and Iran in 2025? 18%

These ones I’m actually a bit unhappy with. Either I believe that Iran is going to succeed at building a nuclear weapon in time, or I believe that someone will intervene and stop them. I should have looked at these questions in conjunction.

Also, on the nuke question I put:

Successful intervention in joint op with Israel: 1/2 * 80% = 40%

Which I believe is 80% that they try, 50% that they succeed if they do. I think that 50% overestimated how difficult it is to destroy static land targets? I should have thought more carefully about the kind of operation needed before assigning odds.

38. Will Elon Musk be the world’s richest person on December 31, 2025? 98.8%

This was clearly way too high, given that Larry Ellison briefly claimed the title.

I think the reason for going this high is first and foremost underestimating the volatility of single stocks: the fact that L.E. could ~double his wealth in half a year is utterly mad.

I got really lucky here, I think a better forecast would have been around 90%.

Appendix: All our predictions

  Me, initial Me, after update ErrorMargin, initial ErrorMargin, after update Randomator, initial Randomator, after update
Will the US eliminate the Department of Education through law or presidential reorganization before 2026? 5 1.5 3 2.5 5 3
Will Jerome Powell cease to hold the office of Chair of the Federal Reserve before 2026? 5.6 2 8 2 10 2
Will the US Congress pass a bill implementing Trump’s tariff policies in 2025? 2.5 2.5 3 3 30 10
Will Israel establish direct governmental control of the Gaza Strip in 2025? 8 4 10 10 40 10
Will mifepristone become significantly restricted or illegal to prescribe for abortions across the US before 2026? 8 4 20 13 15 10
Will Google’s search market share drop below 85% in 2025? 5 4.5 10 7 5 5
Will major components of the Affordable Care Act be repealed or curtailed before 2026? 17 10 15 12 40 15
Will Donald Trump have a positive net favorability rate on December 20, 2025, according to 538? 12 12 13 13 15 15
Will Elon Musk cease to be an advisor to Donald Trump and face public criticism from Donald Trump before 2026? 28 15 30 25 30 30
Will there be at least 1,000 deaths due to direct conflict between Israel and Iran in 2025? 25 18 15 22 20 20
Will there be a leadership change in any of United States’ foreign adversaries in 2025? 16 19.3 45 30 25 25
Will there be a bilateral ceasefire in the Russo-Ukraine conflict before 2026? 28 20.7 25 25 20 25
Will the US unemployment rate in November 2025 be below the rate in November 2024? 18 21 15 15 25 20
Will the US government release additional Epstein documents in 2025? 3 21 40 20 15 20
Will an application to ban AfD be filed at the Federal Constitutional Court before 2026? 65 37 35 40 75 65
Will Iran possess a nuclear weapon before 2026? 68 38 40 35 20 35
Will inflation-adjusted gas prices rise in the US in 2025? 42 44 40 43 45 45
Will OpenAI top the Chatbot Arena Leaderboard on December 31, 2025? 45 48 60 40 15 18
Will a new war or a substantial escalation to a previous war kill at least 5,000 people in 2025? 42 48 45 50 10 45
Will real housing prices in the US increase more in 2025 compared to 2024? 90 50 40 45 70 60
Will the Democrats be favored to win the 2028 US presidential election in the last week of 2025, according to Kalshi? 50.5 50.5 48 48 51 51
Will any rationalist, effective altruist, or AI safety researcher go on the Joe Rogan Experience before 2026? 56 55 63 63 10 25
On December 31, 2025, will Google, Meta, Amazon, Tesla, or X accept crypto as a payment? 18 55 85 70 70 70
Will at least twice as many deportations by U.S. ICE occur in Fiscal Year 2025 compared with Fiscal Year 2024? 30 58 93 78 60 70
Will the 12-month percentage change in the US CPI be lower in November 2025 than it was in November 2024? 45 65 70 70 75 70
Will Benjamin Netanyahu remain Prime Minister of Israel throughout 2025? 78 72.5 60 63 75 75
Will the poverty rate in Argentina be lower in the first half of 2025 compared to the second half of 2023? 93 85 92 97 90 90
Will US federal interest rates at the end of 2025 be lower than at the end of 2024? 92 85 75 80 80 80
Will Nvidia outperform the S&P 500 in 2025? 88.9 88.9 93 93 95 95
Will Argentina’s year-over-year inflation be below 30% for December 2025? 38 92 75 93 25 60
Will semaglutide be taken off FDA’s drug shortage list in 2025? 85 95 90 90 15 30
Will Elon Musk be the world’s richest person on December 31, 2025? 98.8 98.8 95 98 90 95