If by "sharks" you mean "inside traders" then yes.
I took it to be like a pool shark. https://en.wikipedia.org/wiki/Glossary_of_cue_sports_terms#s...
Why Almost Everyone Loses–Except a Few Sharks–On Prediction Markets
21–30 of 107 posts
Re: Why Almost Everyone Loses–Except a Few Sharks–On Prediction Markets
#22I ran the earliest predictions market online at the reboot of The Industry Standard.
Prediction markets fatally suffer from two Problems.
1) large sharks making huge bets at the end (destroying any signal from earlier bets)
2) inside information on poorly written bets.
The solution is -parlay- edit: parimutuel style payouts but that destroys popularity (you are paid out at closing odds not at your time of bet odds spread to sell position).
Re: Why Almost Everyone Loses–Except a Few Sharks–On Prediction Markets
#23This whole prediction market space seems like a 2026 version of ball and cup game betting. Most of the people participating fail to understand that they (and their pointless bets up for harvesting) are the product here.
Re: Why Almost Everyone Loses–Except a Few Sharks–On Prediction Markets
#24I had a thesis two months ago that you could detect predictors with insider knowledge and ride their coat tails and spent some amount of time staring at the data and running some ML algos to detect them. I learned some things about the market during this time, but did not succeed in my detection algorithm. * Polymarket is a bit more transparent with who placed what bet, so it's a good place to go to study winners. *…
> I learned some things about the market during this time, but did not succeed in my detection algorithm. What failed? Was it too late to follow the trend by the time one was identified or something else? It seems much more transparent than trying to reason about say dark pool trades.
I am unfamiliar with working with such signal-to-noise ratios.
* I only had the example trades in the news as 100% confirmed positive trades.
* There are hundreds of millions of dollars in trades a day in Polymarket.
* In Polymarket you can just spin up a new account. If an account spins up, makes a $50k bet and wins, and then has no other activity, was that an insider trader or just someone with a behavioral pattern of spinning up new accounts? Just following up on these types of trades didn't provide a very big edge, as the nature of the trade adjusts the payout percentage.
Re: Why Almost Everyone Loses–Except a Few Sharks–On Prediction Markets
#25I ran the earliest predictions market online at the reboot of The Industry Standard. Prediction markets fatally suffer from two Problems. 1) large sharks making huge bets at the end (destroying any signal from earlier bets) 2) inside information on poorly written bets. The solution is -parlay- edit: parimutuel style payouts but that destroys popularity (you are paid out at closing odds not at your time of bet odds sp…
"The solution is parlay style payouts"
I think you mean parimutuel payouts?
Re: Why Almost Everyone Loses–Except a Few Sharks–On Prediction Markets
#26If by "sharks" you mean "inside traders" then yes.
I took it to be like a pool shark. https://en.wikipedia.org/wiki/Glossary_of_cue_sports_terms#s...
Yes, that'd be the grammatically correct use. But Insider trading has been rampant on the "prediction markets". In short, it's a scam, because gambling is always a scam.
https://fortune.com/2026/04/26/prediction-markets-insider-tr...
Re: Why Almost Everyone Loses–Except a Few Sharks–On Prediction Markets
#27Earlier quoted context omitted.
> At first, it worked. Pederson turned about $2,000 into close to $8,000 by betting on daily snowfall totals in Detroit
I'm not a gambler, but when I consider it I think the worst thing that could happen to me would be to win a substantial but not life-changing amount of money. I think that's where most people get hooked. They get lucky once (or a few times), then get completely sucked in trying to replicate that success.
That particular set of circumstances is the ruin of many a lottery winner.
Re: Why Almost Everyone Loses–Except a Few Sharks–On Prediction Markets
#28Prediction markets are astrology for the boys.
Astrology is more of a cost centre than a gambling venue, unless you consider choosing a life partner based on the stars.
Re: Why Almost Everyone Loses–Except a Few Sharks–On Prediction Markets
#29I had a thesis two months ago that you could detect predictors with insider knowledge and ride their coat tails and spent some amount of time staring at the data and running some ML algos to detect them. I learned some things about the market during this time, but did not succeed in my detection algorithm. * Polymarket is a bit more transparent with who placed what bet, so it's a good place to go to study winners. *…
I used to play penny stocks for fun and it was a blast to be doing $3000 trades and be responsible for 30% of the volume for the day. You can learn a lot about how markets work if you adopt a penny stock, particularly the kind that trades in a wide range where you can buy in at 0.03 and figure "I'll sell when it hits 0.12" and sooner or later it does... then falls back down to 0.02.
You can "trade the news" with penny stocks (this is basically just buying when people first start talking about it then selling when more people are talking about it), but like you say, the liquidity is soooooo low that you have to be really careful if you plan to sell more than a few hundred dollars.
Generally, you're going to lose money - so don't do it.
Re: Why Almost Everyone Loses–Except a Few Sharks–On Prediction Markets
#30I had a thesis two months ago that you could detect predictors with insider knowledge and ride their coat tails and spent some amount of time staring at the data and running some ML algos to detect them. I learned some things about the market during this time, but did not succeed in my detection algorithm. * Polymarket is a bit more transparent with who placed what bet, so it's a good place to go to study winners. *…
I used to work for a sports betting company that identified individuals who were a little too good. The key is to remember that they are addicts and will bet on events regardless of if they have insider knowledge or not, so you have to account for this and not only identify the individuals with insider knowledge, but also what events they have that knowledge about and what they don't.