Trade Idea: 500+ Measles cases in the US before April?

Market: 500+ Measles cases in the US before April?

Return: 426%

Resolved by: End of March

Position size: Medium

Welcome back to The Poly. Our first trade from last week - Will Epstein files be released by Friday - cashed in and gave us an easy 25% gain in four days. Our second trade of last week - Ukraine agrees to the Trump Mineral Deal before April - is still sitting at the 30% where we originally posted about it. As five days have passed and no news has come out about any advancement of the deal, we believe this market is still undervalued. There is an upcoming meeting between the US and Ukraine in Saudi Arabia, in which the mineral deal is meant to be negotiated, but this suggests to us that the progress of the deal has actually backtracked since we originally posted. Before Zelenskyy went to the White House the deal was all but confirmed, but now if there is a need for negotiations it means that the original deal is no longer agreed upon. Negotiations like this take time, especially if there are large disagreements. This deal will likely be signed at some point, but the likelihood of it happening in the next three weeks is likely much less than the 70% suggested by Polymarket.

We also still have the “Will DOGE audit Fort Knox before May?” trade open. That has returned us 125% since we posted the idea, going from 28% to currently sitting at 63%. We still believe this market will resolve to no, but for more risk-averse traders this might be a good time to trim the position considering the large gain across a short couple of weeks.

Today we are looking at the Measles outbreak in the US. As of March 6, 2025, there were 222 confirmed cases, with the majority in Texas (198 cases) and ongoing outbreaks in multiple states. Our research suggests the measles case number in the US may reach over 500 by March 31, 2025, with a 70% probability, based on current trends and outbreak characteristics.

Current Situation

We're seeing quite a worrying measles outbreak right now. According to the CDC's latest update from March 6th, there are 222 cases across the country. Texas is getting hit the hardest by far, with 198 cases just in the South Plains area. New Mexico has about 10 cases too. The disease has spread to several other states as well - Alaska, California, Florida, Georgia, Kentucky, New Jersey, Pennsylvania, Rhode Island, and Washington, plus New York City. What's really concerning is that two people have already died - one death is confirmed as measles-related, and they're still investigating the second one. Vaccination status reveals 94% of cases are unvaccinated or of unknown status, with only 4% having received one MMR dose and 2% two doses, underscoring a significant vulnerability in the population.

Growth Trends and Rate Analysis

Between February 25th and March 6th, Texas jumped from 124 cases to 198 - that's 74 new cases in just 10 days, or about 7.4 new cases every day. Compare that to before February 25th, when they were seeing roughly 4 new cases daily since the outbreak started around January 25th. The situation is clearly getting worse, likely because measles spreads like wildfire when vaccination rates are low.

Looking ahead to the end of March, if Texas keeps adding cases at this current rate of 7.4 per day, they'll see about 185 more cases over the next 25 days. That would push their total to around 383 cases. For the rest of the country, which currently has 24 cases total, they're adding new cases much more slowly - about 0.58 cases per day. At that pace, they'd add about 15 more cases by March 31st, bringing their total to around 39. So nationwide, we're looking at approximately 422 cases by the end of March if cases grow linearly.

However, Measles is a highly-infectious disease; up to 90% of non-immune people close to the infected person will be infected. Infected people can spread measles to others from 4 days before through 4 days after the rash appears. Each infected person potentially spreads it to 12-18 others in communities with low vaccination rates. The health reports are pretty clear about how quickly this can spiral. When we look at what's happening in Texas, there's a clear pattern of acceleration that's pretty worrying.

From February 25th to March 6th, Texas went from 124 cases to 198 cases in just 10 days. That's not just simple addition - it's growing at about 4.9% every single day. You can get the exponential growth rate using this equation: 198 = 124 × (1 + growth rate)^10.

If this 4.9% daily growth continues for the next 25 days, Texas alone would hit around 642 cases by the end of March. Add in the other 39 cases we're expecting from the rest of the country, and we're looking at 681 total cases nationwide. Add in the exponential rate that will likely occur to the cases in the rest of the country, it is likely there will be more than 39 cases from the other states too. That would blow past the 500 mark by quite a bit.

Probability Assessment and Rationale

The 70% probability that cases will exceed 500 by March 31, 2025, was derived by assigning probabilities to different growth scenarios based on recent trends and potential interventions:

Exponential Growth (40% likelihood): Total cases around 680, above 500, reflecting the contagious nature of measles and low vaccination rates, especially in Gaines County.

Constant Recent Growth Rate (30% likelihood): Using the most recent rate of ~14.8 per day for Texas, total cases around 600, above 500, if the high rate continues.

Decelerating to Average Growth (20% likelihood): Using an average rate of ~3.05 per day, total cases around 420, below 500, if public health measures start to slow the spread.

Significant Drop Due to Interventions (10% likelihood): Total cases much lower, below 500, if vaccination drives and isolation are highly effective.

Adding the probabilities where cases exceed 500 (40% + 30% = 70%), we arrive at the 70% probability. This assessment accounts for the recent acceleration in cases, the challenge of containing spread in under-vaccinated communities, and the potential for public health measures to mitigate but not fully stop the outbreak.

Influencing Factors and Public Health Measures

There are a few key things that'll really determine whether we cross that 500-case threshold or not. The biggest issue is definitely the vaccination gaps we're seeing. Almost 94% of the people who've gotten measles this year either weren't vaccinated or we don't know their status. That's huge. Take Gaines County in Texas - according to AP News, nearly 14% of school kids there have vaccine exemptions. That's creating the perfect environment for measles to run wild.

It's not just a Texas problem either. Across the country, kindergarten MMR vaccination rates dropped to 92.7% last year. That might sound high, but experts say we need at least 95% for herd immunity to actually work. We're falling short at exactly the wrong time.

Health officials are scrambling to get ahead of this. Texas health departments are running vaccination campaigns and setting up isolation protocols. They're making vaccines available through local providers and pharmacies, and they're posting updates twice weekly - Tuesdays and Fridays. The CDC is also pushing hard for travelers to get vaccinated since that's how measles often jumps between communities. It's unclear if these efforts will be enough, especially in rural areas where it's harder to coordinate these campaigns. The next few weeks will be critical in seeing whether we can turn this around before it gets much worse.

Conclusion

Our research suggests a 70% probability that measles cases will reach over 500 by March 31, 2025, driven by accelerating growth in Texas, particularly in Gaines County with 137 cases and low vaccination rates for kindergartners, despite public health efforts. This projection is based on detailed analysis of current data, growth trends, and influencing factors, with an acknowledgment of the uncertainty introduced by containment measures and the potential economic strain on rural areas. In conclusion, the 70% probability of over 500 cases by March 31 is much higher than the 19% probability suggested by Polymarket, creating a very lucrative expected value trade.