9 ms·
'Hairdryer used to trick weather sensor' to win Polymarket bet
- guyzero 6mo agoI don't understand who is taking the other side of all these insane Polymarket bets. Is Polymarket doing it?
- 8note 6mo agogambling addicts is the answer
- Groxx 6mo agoThere's quite a lot of ways to interpret this question... but for that day's daily bet: >A temperature of 18C was seen as a 99.6pc probability before the temperature spiked later in the day. 99.6% of them didn't take the insane bet. And at least one of those 0.4% (by value? count? idk) decided to cheat.
- jjice 6mo ago> 99.6% of them didn't take the insane bet. I don't think the actual bet was insane, but the concept of betting on the weather is insane.
- Groxx 6mo agoPeople bet on anything and everything, and the less controllable the better, afaict. "I'll bet you $5 that snail will eat the cucumber before the broccoli" - > "fuck yes, make it $20" is 100% a thing I could see happening. Weather is significantly easier to do every day though, unless you know a snail farmer with a twitch stream (if so, hook me up!).
- marton78 6mo agoThere are legitimate reasons to bet on the weather. If you're a farmer, betting on drought can be a hedge against a bad year.
- bloppe 6mo agoIf polymarket were staking wagers on its own platform, then it would have to worry about the integrity of the contracts, which is a nonstarter
- mcmcmc 6mo agoWhy do you think it’s a nonstarter when so many of these new platforms do commit fraud all the time and get away with it? It’s only a problem if they get caught, and then only if people actually pay attention enough to care
- tantalor 6mo agoYou're wrong. The big prediction markets (Polymarket, Kalshi) employ in-house market makers and contractors. They provide liquidity for less-active contracts. They generally are not profitable.
- thimabi 6mo agoI don’t understand why these bets are allowed at all. Can one just make an account there and bet in anything? The whole “prediction market” charade is increasingly proving to lend itself to abuse. I hope regulations catch up with it soon, otherwise more shenanigans will follow.
- logicchains 6mo ago[flagged]
- VectorLock 6mo agoCertain no negative externalities from these shenanigans here, let people do what they want to do regardless of how it harms others.
- logicchains 6mo ago[flagged]
- hrimfaxi 6mo agoWhy do airports collect weather data at all? Just for fun?
- hrimfaxi 6mo agoShould it be legal to be able to bet when someone will die?
- logicchains 6mo agoIt's already legal for two individuals to bet when someone will die. It's illegal to murder someone; we don't need extra laws to stop that.
- hrimfaxi 6mo ago
- WarmWash 6mo agoCasinos are purpose built to make you lose. People still show up compulsively everyday.
- gowld 6mo agoCasinos have many games with exact payout odds posted. Polymarket does not.
- AndroTux 6mo agoSo? There’s no game with payout odds in your favor. Lotto (at least where I live) also shows the odds, which are always ridiculously low. Still, people play, because the human brain isn’t built to understand odds. It’s essentially worthless as a metric.
- GBeastMode 6mo agoIt’s not really a bug - it’s a feature. Casino software is designed from the ground up to keep players engaged for as long as possible, which is where all those retention and engagement mechanics come from. It’s also important to understand that the “house edge” isn’t about luck - it’s pure math built into the algorithms (RTP, volatility, etc.). At the same time, a lot depends on the operator. Different providers offer different levels of flexibility, and the casino owner ultimately decides what kind of conditions to offer players. Here’s a solid breakdown on why platform flexibility matters and how it’s used in practice: https://thetradable.com/press-releases/why-flexibility-and-scalability-of-turnkey-solution-providers-define-success-in-2025 https://thetradable.com/press-releases/why-flexibility-and-s...
- hx8 6mo agoIt sounds like the other side of the bet was the actual winning bet when compared to Truth. Maybe they have great climate models and actually make a bet that they have an edge on. Maybe they have a gambling problem. Either way, they are the victims here.
- bloppe 6mo agoThey are the victims of Goodhart's law. The contract unambiguously said it would be decided by the reading of that particular thermometer.
- seanalltogether 6mo agoPeople with cryptocurrency and no idea what to do with it.
- christkv 6mo agoNope the only money on the line is the people betting. Polymarket gets their cut and has "no monetary risk"
- dymk 6mo agoKalshi places bets in their own marketplace - but they have all the data and lots of analysts, so the house still wins on average.
- somenameforme 6mo agoThere are communities larger than you'd expect around just about every topic imaginable. I'm certain there are temperature enthusiast groups, especially given its adjacency to climate stuff. It's probably going to be people mostly betting on something they have better than average knowledge of. I'd be interesting to compare the 'normal' majority temperature predictions from polymarket to local weather station predictions. I'm betting polymarket wins, by a wide margin. For instance chess wagers on polymarket are super interesting because it's far more informative than a chess engine, even though engines are much stronger than any human. The nuance is that engines don't appreciate human factors like how easy/hard a position is to play. And so an engine might just say 'dead draw', whereas a strong human can say 'nah, white has very good winning chances here' - and the polymarket wagers end up reflecting that. And so there it's mostly strong players making money from people who think turning on their engine and betting based on what it says is something nobody else must have thought of.
- skipants 6mo agoPeople that haven't read Black Swan and bet on every "sure bet" they can see
- qurren 6mo agoI've been quite successful trading weather prediction markets. The prediction markets were never about predicting outcomes. If that's the level you are playing on, you're playing at the lowest possible level, and probably won't win. The markets are now about properly modelling other peoples' manipulation of prediction. That's how Wall Street works as well. Companies can beat earnings and their stocks crash immediately after. It makes zero sense if you just model companies. It makes full sense if you stochastically model how an ensemble of humans behave under incentives and human-written bots behave under human-written policies. "Hairdryer sometimes get pointed at the weather sensor" and "Government sometimes fudges jobs/CPI data" are more or less the same thing. Build it into your model. That's the level you need to play on to profit in these markets. It's not that different from how a chess engine works.
- Coneylake 6mo agoI am getting into trading on my own (my main job was in machine learning and I studied math in university). I've also come to a similar conclusion that you pretty much have to model these "manipulations" on top of the statistics/Brownian-motion-driven behavior of any security. I am currently working on a hybrid model for something on Polymarket but it's not yet sophisticated. Do you have any resources that you can point me to that expand on this very idea of adding human behavior to financial modeling?
- qurren 6mo agoWithout giving away my exact strategies, I'm also an ML engineer and I'll just say that ML is in 90% of cases the wrong tool, whereas simple regressions and scatter plots will unearth loads of statistical anomalies if you know where to look. You want to find anomalous behavior then hone in on how to make them your counterparty. ML can help you optimize things after that, but locating diamonds in a soup of noise is not really where ML shines.
- ethtdhdrh 6mo agoSays "prediction markets were never about predicting outcomes", writes long winded tripe stating that "prediction markets exactly about predicting outcomes". Thank you Tai Lopez.
- mndgs 6mo agoBeautiful con, tbh. I don't welcome this behavior (borderline criminal), but you have to admit - well played.
- hughw 6mo agowell over the border
- Petersipoi 6mo agoWhich law? I genuinely don't know. These prediction markets are new enough that I'm not sure if the laws have been written yet.
- w-m 6mo agoJohn Oliver had a segment on prediction markets this week. It covers insider training and opportunities for blatant manipulation like this, well worth checking out. The example in the Last Week Tonight segment was betting on dildos being thrown on court during a WNBA match. And then travelling to the match to throw the dildo. [0] https://www.youtube.com/watch?v=ZN4njIQcSR4 https://www.youtube.com/watch?v=ZN4njIQcSR4
- lostlogin 6mo agoThe WNBA bit was less alarming than the betting on various aspects of the US + Israel versus Iran war. All gross.
- Petersipoi 6mo agoWhy is the WNBA alarming at all (other than the fact that we shouldn't be throwing dildos on the court at all, of course)? I'm just not sure why anyone would take a bet against someone who can single handedly make their side win. It would be like someone making a bet that I won't eat a hot dog for lunch tomorrow. Of course I'm going to eat a hot dog for lunch tomorrow. Why is there anything alarming about that? It's just stupid that anyone is taking the other side of that bet.
- ctime 6mo agoBetween this and crypto cryptocurrencies (which obviously can be used to make bets) I don’t know which is more destructive to society
- toenail 6mo agoFiat money is obviously more destructive, but you'd have to do some basic research to figure that out.
- anonymars 6mo agoHere's a thought experiment for you: if "fiat currency=bad" and "hard money=good", why did the world collectively switch? Where are all the prosperous societies that held the line?
- singingtoday 6mo agoThere is an answer the crypto enthusiasts have to this, but since I'm not one of them I wouldn't do the argument justice. The short version is, it's about control and power.
- fyzix 6mo agoThey were forced to switch when the dominant military power decided to rugpull on August 15, 1971.
- anonymars 5mo agoExactly how did the US suspending conversion of its dollar to gold prevent other countries from using hard currency instead of fiat for their own?
- logicchains 6mo agoHow is it even remotely as destructive as casinos, where the odds are always against you? From a probability perspective Polymarket is much more fair, as you actually have positive expected value if you have an information advantage.
- ambicapter 6mo ago> There are no indications so far that the successful punters have had to return their winnings. However, the data source for Paris’s hottest temperature has since moved to a sensor at the smaller Paris-Le Bourget airport. Here's the negative externality that no one will care about. There's no reason gamblers won't repeat this stunt, until us poor schmucks who just want an accurate temperature reading have to build a fortified compound in order to do so.
- AustinDev 6mo ago>There's no reason gamblers won't repeat this stunt, until us poor schmucks who just want an accurate temperature reading have to build a fortified compound in order to do so. The issue here is you'd need a lot more land because any asphalt near a temp sensor is going to give you bad data.
- naikrovek 6mo agoWhat do you think taxiways are made of? Or parking lots?
- malfist 6mo agoThats just not true. Generally you want to place a sensor 5 feet away from any structure. That's not a lot of land
- sixothree 6mo ago> The issue here is you'd need a lot more land because any asphalt near a temp sensor is going to give you bad data. Ah yes. The way to measure temperature in the city is to move the thermometers outside of the city. Makes perfect sense.
- hrimfaxi 6mo agoI mean, there are plenty of negative externalities that this type of gambling brings that are much worse, but at least in this case it does appear that authorities are investigating. At the very least I would expect some law to be broken if interfering with official weather data collection at an active airport.
- jbrowning 6mo ago> While it is unclear how the temperature might have been manipulated, one possibility shared on weather forums was that a battery-powered hairdryer could have been used, according to Le Monde newspaper. Clickbait headline FWIW.
- gowld 6mo agoFlag the submission. Telegaph is a disreputable tabloid. There are better sources. https://www.tradingview.com/news/cointelegraph:1c00dcc26094b:0-polymarket-traders-win-37k-after-paris-weather-data-glitch-raising-suspicion/ https://www.tradingview.com/news/cointelegraph:1c00dcc26094b...
- dlenski 6mo ago> On April 15, one trader made $21,000 (£15,600) betting that the maximum temperature would not be 18 degrees, data from Polymarket show. A temperature of 18C was seen as a 99.6pc probability before the temperature spiked later in the day. I believe that these are the specific Polymarket bets in question: April 6 (https://polymarket.com/event/highest-temperature-in-paris-on-april-6-2026 https://polymarket.com/event/highest-temperature-in-paris-on...): this appears to have been something of a "test run", since the odds weren't particularly lopsided until it suddenly spiked in the evening local time. April 15 (https://polymarket.com/event/highest-temperature-in-paris-on-april-15-2026 https://polymarket.com/event/highest-temperature-in-paris-on...): the odds were quite lopsided in favor of 18°C, until suddenly reversing in the evening. This is presumably where the fraudsters made all their money.
- sva_ 6mo agoThe sensor readings do look suspicious: april 6 https://www.wunderground.com/history/daily/fr/mauregard/LFPG/date/2026-4-6 https://www.wunderground.com/history/daily/fr/mauregard/LFPG... april 15 even more so: https://www.wunderground.com/history/daily/fr/mauregard/LFPG/date/2026-4-15 https://www.wunderground.com/history/daily/fr/mauregard/LFPG...
- ChrisArchitect 6mo ago[dupe] https://news.ycombinator.com/item?id=47869664 https://news.ycombinator.com/item?id=47869664
- ikeboy 6mo agoReminds me of when I made about $40k finding a source that had CO2 data in close to real time when other people were tracking one about 12 hours delayed See https://misinfounderload.substack.com/p/tales-from-prediction-markets https://misinfounderload.substack.com/p/tales-from-predictio...
- I_Write_It 6mo agoThose are great stories in the article!
- nanna 6mo agoWhy is Polymarket legal? I just don't understand.
- tantalor 6mo agoWhy wouldn't it be
- Eisenstein 6mo agoIt creates financial incentives for anti-social behavior and the proposed benefits of it being a way to determine truth are dubious and self-serving and would not be worth the societal cost regardless.
- dymk 6mo agohttps://en.wikipedia.org/wiki/Insider_trading https://en.wikipedia.org/wiki/Insider_trading
- sethops1 6mo agoBecause we have laws that regulate gambling. "Prediction markets" get around them by bending the definition of the word "gambling".
- dabinat 6mo agoFor a while it wasn’t in the US. They now have a cut-down version. But a lot of people use VPNs to access the less-restricted international version. So to answer your question, a lot of users are using it in a way that’s illegal.
- cogman10 6mo agoIt and Kalshi are not. But we don't have regulators that want to enforce the law here. Polymarket in particular started out using crypto and off shoring with a "not legal in the US, wink wink" to get try and dodge regulations.
- happyopossum 6mo ago> While it is unclear how the temperature might have been manipulated, one possibility shared on weather forums was that a battery-powered hairdryer could have been used Man I hate headline writers… We’re I contracted to (legally and ethically) red team a temperature station, a “battery powered hair dryer” would be pretty low on my list of techniques for a number of reasons. First attempts would involve mirrors - parabolic or otherwise- to heat the device from a distance without potentially affecting wind speed / direction sensors.
- literalAardvark 6mo agoBlack cardboard stuck to the sensor and a transparent plastic bag around should do the trick with very little effort. Or you could hold it until it ticks 18.9 or whatever the bet was.
- dwa3592 6mo agoIdea : "Manipulation of real world events because correct prediction of real world events is incentivized." Try to scale this anywhere from hairdryer usage to trip temp sensors to nuclear bombs going off in poor countries.
- strogonoff 6mo agoBetting against what is widely considered as “expected”, “reasonable” is such a major source of profit when one can influence the income. Whether it’s a temperature sensor one can breathe on or movement of troops one can control or influence[0], the idea is the same—except in one of the above you can add “death and suffering” in addition to some unfortunate gamblers losing their money. A depressing thought: it will only tip in favor of common good when the probability of something that we today consider “normal” becomes so small that betting on that finally becomes profitable to insiders with influence. Imagine that world… [0] No, I’m not going to change my writing style because it is considered a “tell” of LLM use.
- dugidugout 6mo agoI don't mean to detract from your point, but regarding your footnote, you seemingly have. Unless it is in your writing style to make direct asides about how one may infer your message was procured.
- strogonoff 6mo agoFair point, though it’s isolated to a footnote.
- efitz 6mo agoThe guy will be solely responsible for half a degree of global warming next year.
- phendrenad2 6mo agoFun fact: Kalshi runs ads that start with a guy saying "I just made money because it snowed!" Make of that what you will.
- waltbosz 6mo agoIf you have 3 minutes, here's an apropos BBC audio comedy sketch. https://youtu.be/ub01udUz7ns?si=OBMKdK6RED3aZMEq&t=15 https://youtu.be/ub01udUz7ns?si=OBMKdK6RED3aZMEq&t=15
- krunck 6mo agoQuite literally EVERYTHING around us is now subject to possible manipulation by these idiots if they think they can profit. Even the US Government has executive and legislative officials profiting from secret information they know from doing their duties. I wonder when someone who does cloud seeding will place a bet about rain at some unlikely time and place. Or the next large forest fire.
- Tangurena2 6mo ago> I wonder when someone who does cloud seeding will place a bet about rain at some unlikely time and place. Each year, one of my state's legislators introduces a bill to outlaw chemtrails [0]. It never leaves committee. This year, he added the plot of Termination Shock [1] to his bill. This proposed legislation already includes "cloud seeding" as a crime. Penalty of $500k/day and each day is a separate crime. 0 - https://apps.legislature.ky.gov/record/26rs/hb60.html https://apps.legislature.ky.gov/record/26rs/hb60.html 1 - https://en.wikipedia.org/wiki/Termination_Shock_(novel)# https://en.wikipedia.org/wiki/Termination_Shock_(novel)#
- aeternum 6mo agoAnd as a result we should gain stronger epistemology. How many cities base their official temperature readings on just a few sensors rather than a widespread network? Sure you might argue, maybe this was an issue with Polymarket choosing a weak source rather than the gov, but is that really true? If you question measurements like this you quickly get labeled an climate denier. IMO this is good for the world, temp measurements should be based on thousands of sensors not just one. And if cloud seeding works, all the better for humanity, it's likely a key to terraforming future planets.
- thrance 6mo agoYou completely missed the issue. Météo-France already has tens of thousands of stations across the country, they're very obviously not basing their entire models off of one sensor in Paris CDG. The degenerate idiots from Polymarket bet on this particular sensor. There's no law preventing people from betting on single sensors. And we can't make laws preventing people from acting on the world in all the diverse ways that can be exploited to cheat in prediction market. We should just blanket ban this negative-value industry. We don't want people betting on forest fires and then starting them.
- jerf 6mo agoThe libertarian argument for prediction markets is really beautiful. It's just a pity it basically depends on all participants in the prediction market being basically unaware that they are participating in a prediction market, and being oblivious to the incentives to create the outcomes they are predicting by the very act of predicting it with money. But other than that minor detail, that little minor catastrophic flaw in the foundation, it's a beautiful argument. I think we can call it as a society. It's a failure. We can go back to banning them, not just for moral reasons, but just pragmatic ones. The theory doesn't work. The supposed benefits don't manifest, and "unanticipated" costs to everyone do. We did the experiment. (Again.) We can close this out now.
- FrustratedMonky 6mo agoNow bet that climate deniers will use this as example that lots of temperature data is faked.
- dzdt 6mo agoThis is small potatoes compared to the rain gauge tampering farmers were doing in Colorado. There was a recent conviction for $6.5 million dollars of fraud against the federal crop insurance program! https://www.justice.gov/usao-co/pr/two-southeastern-colorado-farmers-sentenced-federal-prison-and-will-pay-over-65-million https://www.justice.gov/usao-co/pr/two-southeastern-colorado...
- jandrewrogers 6mo agoPeople have no idea how pervasive this is globally.
- bombcar 6mo agoIf it exists, and money can flow, it will be gamed.
- anigbrowl 6mo agoWe should have much stricter penalties for fraud. Vastly more money is stolen this way than by petty theft or robbery, but the perpetrators tend to get off very lightly by comparison.
- cbluth 6mo agoIt's an offset for the amount of effort and forethought put into the fraud
- RugnirViking 6mo agoWhat's an offset? The money stolen from other people? I can't understand what you mean
- sysguest 6mo agowell the bravery for robbing a bank deserves some respect, not jail time sexual assulters deserve respect due to their manliness and will-to-action hmm can't see what's wrong here? well that's your intelligence level
- sebastianconcpt 6mo agoReminds me of not long ago someone writing about "Everything is Lies Now"
- johnhamlin 6mo agoRemember when it was just common sense that letting people gamble on things would undermine the integrity of those things?
- LanceH 6mo agoThe critics of prediction markets needs to decide if they are against the markets because they are gambling, or because they aren't gambling.
- tsunagatta 6mo agoNo, they don't. It's fine to be against them in both ways, considering that the platforms themselves can't decide if they're gambling or not.
- _trampeltier 6mo agoCheating with weather sensor is not new. Wrecked rain gauges. Whistleblowers. Million-dollar payouts and manhunts. https://news.ycombinator.com/item?id=41485560 https://news.ycombinator.com/item?id=41485560
- iambateman 6mo agoAt some point, the market for markets will demand better regulation than this. But I find it a little absurd that anyone is still putting their money into these markets with story after story of obvious fraud.
- guizadillas 6mo agoThey spent a lot on marketing, it doesn't surprise me at all
- sbarre 6mo ago> I find it a little absurd that anyone is still putting their money into these markets with story after story of obvious fraud. Then you do not understand gamblers. They make emotional decisions not rational decisions. That's why the lottery works (i.e. "someone has to win")
- dlev_pika 6mo agoIs it clear already how bad of an idea, and social disservice, Polymarket/Kalshi are?
- cindyllm 6mo ago[dead]
- gmd63 6mo agoWonder how the founders/board/investors of the bad incentives factory would manage their site after a massive crowdfunding campaign bet that they'd all still be alive in 2027.
- vibe42 6mo agoOutside Trading.
- mkhpalm 6mo agoHair dryer? Or something like a mirror from a comfortable distance?
- sebastianconcpt 6mo agoThe chapter of fake-news is over folks. We just started the everything is a lie unless the opposite is proven.
- nh23423fefe 6mo agolies were invented recently?
- sebastianconcpt 6mo agoThey are a human factory setting that AI is amplifying to unprecedented new levels by making engineering them in industrial scale brutally cheap.
- nh23423fefe 6mo agolike language, or religion, or paper, or printing, or radio. now? now is when lying is problem? not anytime in the previous 500,000 years. now is when civilization will collapse because lies? aren't autonomous agents suppose to navigate complex environments? this doesn't make sense. i dont gamble on weather at french airports.
- bombcar 6mo agoApparently you can gamble on how many cars drive past a traffic camera in a given timeframe. Traffic jams for cash now is a reality.
- janalsncm 6mo agoProbably the clearest counterpoint to the theoretical utility of prediction markets: it creates a financial incentive for influencing future events. Today it’s the temperature at an airport in France. Maybe another day it will be the lifespan of an geopolitically important person.
- insane_dreamer 6mo agopolymarkets are a curse; they'll never be able to stamp out the perverse incentives. I can't wait until we wake up to the fact that they should be banned. we have a whole government department SEC and complex reporting laws just to try to stop manipulation of the stock market for profit, and that's with a very small scope (stock price) -- the polymarket scope is theoretically infinite, there's no way to regulate that people should watch Nightcrawler for an idea of where this this sort of thing can lead to
- johnleslie_pm 6mo agoThis is a textbook oracle manipulation problem, and it's one that prediction market designers have been worried about since the early Augur days. The fundamental issue is that when market resolution depends on a single data source (one weather sensor), the cost of manipulating that oracle can be far less than the payout from the market position. A hairdryer costs $20; the market position could be worth thousands. The interesting design question is how platforms should handle resolution disputes like this. Polymarket uses UMA's optimistic oracle, which allows anyone to challenge a resolution within a dispute window. But that only works when someone is incentivized to challenge. If the manipulator holds both sides of the market at the right ratio, they can profit even if the resolution is later corrected. Serious prediction markets will eventually need to adopt multi-source oracle designs the way DeFi lending protocols moved to Chainlink-style aggregated price feeds after the flash loan attacks of 2020.
- edge_trader_41 5mo ago[dead]
- edge_trader_41 6mo ago[dead]