[jcfrei]

I'm surprised prediction markets don't get more support here on HN. There's a lot of benefit in having a probability estimate for various kinds of events. One example of many: https://polymarket.com/event/may-2026-temperature-increase-c

These markets are a straightforward way to cut through all the noise of the current media conglomerates. Rather than getting bombarded by inflated headlines a glance at polymarket or kalshi is often enough to know whether something is actually happening or it's just the media corporations trying to get your attention.

Of course there should be limits with regards to what kind of markets are allowed on these platforms. But in a lot of areas there's genuine price discovery happening that's not available anywhere else.

[gottorf]

Funny, someone cheated a temperature-related bet a few weeks ago: https://www.npr.org/2026/04/23/nx-s1-5797876/polymarket-pari...

[mapmeld]

It's very strange that they think prediction markets "cut through all the noise of the current media conglomerates" and yet the temperature bet is easily manipulated, and any bets about war and other foreign affairs are resolved by reading news reports from the field and not some new group of independent arbitrators or investigators. The war journalists are even being pressured by the gamblers to change their reporting https://www.timesofisrael.com/gamblers-trying-to-win-a-bet-o...

[water-data-dude]

Prediction markets seemed neat when I first heard about them, but they've proved to have "theory meets the real world" externalities I wouldn't have ever considered. Insiders betting on (and possibly influencing) military/diplomatic stuff, reporters getting threatened, weather stations getting hit with hairdryers. It's wild.

[ekianjo]

And those weather stations only have 1 degree celsius precision?

[bitmasher9]

1. I have only moderate confidence that the odds on prediction markets represent true odds.

2. I think the existence of prediction markets can change the outcome of events. See the Super Bowl Streaker as an example.

3. I don’t have a strong use for prediction market odds. In the few areas of my life that require forecasting I have sources of information i understand and trust more, sometimes with private data not available to the general public.

[jmye]

> 3. I don’t have a strong use for prediction market odds. In the few areas of my life that require forecasting I have sources of information i understand and trust more, sometimes with private data not available to the general public.

100%. I have no earthly idea what the value of these markets is for things I'm not an expert in (I assume they're roughly equivalent to asking the bots and teenagers on Reddit and pretending that's crowd-sourcing, given what they show in things I understand well), and I have no use for them in things I am an expert in.

But hey, at least government employees/soldiers can cash in on secret operations before they happen? That's fun, or whatever.

[mcmcmc]

90% of the activity is sports gambling or insider trading, there’s no benefit that outweighs the negatives

[ZeroGravitas]

That market doesn't look very useful. Seems to resolve only a few days before at the time that weather forecasts would be available.

[gwerbin]

Prediction markets were a lot more useful and benign when it was nerds staking small amounts of money for fun. I still think they're fun but it's clear that the prediction market platform companies aren't interested in staying a fun niche business for nerds.

[ekianjo]

Very difficult to have good faiths actors participating in prediction markets. A lot of manipulation is possible and of course insider trading.

[jerf]

They don't work. They only work if all the participants in prediction markets don't notice their incentive to cheat the market. One example of many: https://moneywise.com/investing/cryptocurrency/polymarket-ri...

A market that only works as long as participants in the market also pretend that they aren't in a market is nonfunctional.

Let all reasoning be silent when experience gainsays its conclusion. The beautiful libertarian theories have failed.

[jrflo]

I think this is far from widespread. It's very difficult to tamper with the majority of markets, and nearly impossible to do so without getting noticed (hence, the news story about this case).

[jerf]

I chose that example precisely because even by prediction market standards it shows the degree to which people will go to skew the market.

The much more popular method of making bets in a variety of ways to skew the system, use all the power of financialization to manipulate values of contracts independently of the underlying measurement, and everything that we're already seeing in quantity and abundance ruins the utility of the market as a prediction market.

You say it's really hard and can be neglected... I say it's already happening so much that the putative value of the markets is ruined. I wave at all the news already written about it and the ongoing flood of news that will continue. The system is fundamentally broken, does not work, and will never work. The theory only works if the value of the prediction market is somehow completely isolated from the value of the things under prediction, but the prediction market itself is the engine for destroying that assumption.

[NeutralCrane]

You need a prediction market to know if the Second Coming of Christ is imminent?

[jrflo]

I agree that there's something interesting here, but the majority of markets are absolute garbage. "Drake Iceman First Week Album Sales", "Arsenal vs Burnley", "Another GTA 6 Trailer Released by May 31", for instance. I am much more interested in the price discovery on markets relating to politics, global trade, pandemics, etc., but sports betting has proven to be largely a net negative for society imo.