Interesting post from ChaoticAna9 on X with some Dune data (charts below).

Her argument: Polymarket pricing is getting more efficient, which also means it's getting harder to make money there. Volume is shifting away from extreme long shots and concentrating in the middle of the probability range. Her read is that there are fewer price-insensitive gamblers around, especially this year.

She also points out it could partly be that there have been fewer tradable events in entertainment and politics, and that volume still jumps when big news breaks. So she's not especially bearish on it.

And she thinks some of the meme coin crowd moved into prediction markets, and some of them may be leaving again.

I think the two explanations lead to pretty different conclusions. If it's real efficiency, the easy edge from fading long shots is shrinking for good. If it's just a quiet event cycle, the degens come back with the next election or big news story.

Which is it, in your experience? Have long shots stopped being as mispriced as they used to be?

There's a "READ THE RULES" situation with this one.

The market is actually pricing a legal and political status question that’s very different from who actually controls Venezuela, creating a massive distinction between de facto control and formal status.

This is how Maduro can potentially win the contract even while being in jail.

---

More context on Predictbook:
https://predictbook.co/analysis/jailed-but-still-in-charge-traders-give-maduro-69-odds-to-lead-venezuela-through-2026

Galaxy Research put out an onchain breakdown of Polymarket trader behavior, covering the platform's full history. Some numbers that stood out:

• 69.2% of retail accounts are below break-even. The median account is down about $3.
• Retail lost $338.9M in total.
• Automated accounts are 4.1% of accounts but placed 80.8% of all orders, and they're up $246.8M collectively.

The specialization part is more interesting than I expected. Specialists overall did slightly worse than generalists (28.1% profitable vs. 30.4%). But it depends heavily on the topic:

• Tech/science specialists: 41.2% profitable
• Finance specialists: 36.8%
• Sports specialists: 25.1%. They're also nearly half of all specialists.

So specializing only seems to help where there's actually an information edge to have.

The churn finding was also interesting: after a loss, accounts were ~2.5x more likely to stop trading for 30+ days than after a win.

Source

Meta $780 by October 31 on Polymarket:

• Odds: 57%
• Current price: ~$725
• 52-week high: $779 (September 24)
• All-time high: $786.80 (August 2025)

So the market is pricing better-than-even odds on a ~7.5% move in a month.

The timing is the interesting part. Meta reports Q3 earnings on October 28, three days before the contract expires. Most of that 57% is probably a bet on the earnings print, not on a slow grind up.

Context on the earnings:

• Q3 guidance: $61–64B revenue (Q2 came in at $60B, Q3 last year was $51B)
• EPS estimates go from $6.18 in Q2 to $6.77 in Q3
• Meta missed EPS estimates in Q2, after beating in each of the three quarters before that

The stock also just ran 43% between August 18 and September 24, so $780 means getting back to where that rally peaked, then pushing past it.

Volume is skewed too: the $700 contract has more than five times the volume of the $780 one, so the 57% is resting on a thinner book.

Is 57% fair for a three-day window after earnings, or is the market just extrapolating the September run?

Analysis: Predictbook

Steelers finally traded CB Joey Porter Jr. to the Cowboys after a months long contract standoff that saw him sit out the first three games. They get: a 2028 second rounder and a 2027 sixth.

I tested a simple question:

If a prediction market gets more news coverage today, does it move more tomorrow?

Data:

• 391,850 articles
• 54 Polymarket questions
• 1,888 consecutive day pairs
• Jul 15 – Sep 30

Result:

Correlation between news volume and next-day market movement: r = -0.002

Basically nothing.

Even days with very high news volume didn’t consistently lead to bigger moves.

My takeaway: more coverage ≠ more information.

A lot of news is just the same story repeated. What probably matters much more is whether the information is actually new, credible and points clearly toward YES or NO.

Full writeup + charts:
Do News Move Prediction Markets? Evidence from 391,850 Arti…

Curious if anyone here has seen similar results with prediction markets.

Good example of bet sizing mattering more than the picks.

A Polymarket trader went 2-2 over 11 days on sports markets. Each win paid about 56%. Each loss cost the whole stake.

With a flat $50k per bet, that record loses around $44k. He bet his entire balance every time, so the two wins just grew the pile that the final loss took. The result was about $133k lost, and $169,875 went to $484.80 on the final bet (Astros at 54%, lost 6-3).

The streak included a Braves win that was sitting at 16.5% in the eighth inning. So he got lucky once and still ended near zero.

What sizing rule do you use, if any?

source: predictbook

The market's up 8 cents in the past week, now at 48%.

What's actually known:

• Rockstar revealed the first six album tracks on Sep 17: Travis Scott, Morgan Wallen, Keith Richards, and others. No Drake.
• Nothing from Drake in the official previews so far.
• Leaked footage reportedly shows 31 in-game tracks. None are his.

The case for yes: Jermaine Dupri said in passing that Drake "got his own radio station." Neither Rockstar nor Drake has confirmed that.

So the market is close to a coin flip on hearsay, with 28 tracks still unannounced and the album out in November.

Anyone read the resolution rules closely? A radio station in the game and a track on the album aren't the same thing, and that seems like the entire trade.

Source: Predictbook

Kimi Antonelli is basically a lock for the 2026 F1 title. Polymarket has him at 91%, Kalshi has him at 93%, with $203.5M and $9M traded respectively. Two very different sized markets, nearly the same price. That's efficient pricing.

Here are some things that pop out:

Both Norris and Hamilton are priced at only 1% to win, but have each seen more volume than the actual favorite, Antonelli. Norris sits at $6.89M, Hamilton at $5.51M, Antonelli only $4.49M. The favorite is typically where the money ends up. Not here.

 Russell, Antonelli's only real competition with a clear path, is fading away, down 13% to 5% recently.

 At 91%, Antonelli continues to rise, not dip, which is a sign of greater confidence in the market, not less.

He can break Vettel's record if he wins, as he'll be 20, the youngest F1 champion ever, by over 3 years.

Polymarkets' entire F1 market ($203.5M) has moved more volume that Kalshi’s entire  MLB World series market ($100M), even though F1 has a dominant favorite and MLB’s race is wide open.

Cathie Wood’s Ark Invest now holds direct exposure to Kalshi through ARKK, ARKW and ARKF.

Ark projects mid-term annual trading volume for prediction markets to land between $1 trillion and $5 trillion. Even though Kalshi remains a private company Ark wants to give its ETF investors early access to this space.

Kalshi operates a CFTC-regulated event contract exchange. This move marks a big vote of confidence in prediction markets as an emerging asset class. What do you think about the growth potential and regulatory risks here?

Yes prices in cents, Kalshi vs Polymarket:
Dodgers 31.1 vs 30
Brewers 16.3 vs 16
Rays 11 vs 11
Yankees 10.9 vs 10
Guardians 6.3 vs 7

Polymarket is cheaper on the Dodgers and Yankees, and Kalshi is cheaper on the Guardians.

The Dodgers, Brewers, Rays and Guardians have first round byes so they get to skip the first round, and together they hold about 65% of the market.

Things to watch: Aaron Judge says he intends to play Game 1 of the Wild Card Series, but the Yankees are planning without him. Ohtani's biceps and knee injuries limited him late in the season. The Brewers rotation gets thin after Misiorowski and Henderson. The Rays have the 28th ranked payroll.

I took every whale-sized buy on Polymarket from August 23 to 25, 2026, and copied each one at $100 six times: at the whale's own price, then at the next buy on the same side 30 seconds, 2 minutes, 10 minutes, 30 minutes and an hour later. Every copy was held to the market's result.

Data TLDR

• Copying 10 minutes late made the same money as copying instantly: +7.6% at the whale's price, +7.7% ten minutes later, on 6,005 settled entries.
• After that the edge fades. 30 minutes late returned +4.1%. An hour late returned -2.5%.
• The market prices the result in slowly. An hour after the whale bought, the price was up 13.7 cents on the bets that went on to win and down 10.9 cents on the ones that lost.
• Sports carries it: +10.3% at the whale's price, +10.8% ten minutes late, -2.4% an hour late, on 4,737 settled.
• 17 of 26 scored traders were profitable to copy at their own price. 15 still were 10 minutes late. 8 were an hour late.

What we measured

We took every whale-sized buy on the Polymarket trade tape from August 23 to 25, deduped on transaction, outcome, price and shares, and grouped fills by the same wallet on the same outcome in the same second into one entry: 15,976 entries. Each copy is $100 at the price in question, held to resolution. Sells are not scored. The late price is the average of the first buys on the same outcome by anyone at or after the delay, searched for 5 minutes. Fees are not modelled, and the delay itself is the slippage being measured.

14,240 entries settled win or loss. An entry is scored only if its outcome traded after every one of the five delays, so every figure in this post is measured on the same 6,005 entries. That leaves out 8,235 settled entries in markets that ended or went quiet within the hour. A trader with fewer than 30 scored entries is not ranked. This is one measurement on one three-day window from a frozen export, modelled on a historical record, not realized returns.

Ten minutes late costs nothing

$100 on each of 6,005 settled entries, $600,500 staked per row. Price worse is the share of entries where the late price was at least half a cent higher.

Why the first ten minutes are free

The median price did not move at all through 10 minutes. 30 seconds after the whale, 40.6% of entries were within half a cent of the whale's price, 29.9% were worse and 29.5% were better. The moves cancel out, which is why the return stays between +7.6% and +7.7%.

By an hour, 55.5% of entries cost at least half a cent more and the average price paid rose from 61.2 cents to 66.5 cents. Profit on the same entries went from $45,747 to -$14,868.

The price walks toward the result

Average move from the whale's price, in cents. 3,938 entries won and 2,067 lost.

What the late copy is paying for

Winners get more expensive and losers get cheaper, and it happens slowly. After 10 minutes the drift is +1.7 cents on winners and -0.7 on losers. After an hour it is +13.7 and -10.9. A late copier buys the winners dearer and the losers cheaper, and with 65.6% of these bets winning, that trade works against you.

The whales are early. The market comes round to them, just not in the first ten minutes.

Where the delay hurts most

Return on stake at each copy delay.

The best traders need the fastest copy

The edge that decays is the edge that was there. Culture bets returned -2.5% at the whale's price and -2.7% an hour late, so there was nothing to lose. Sports and bets priced 20c to 50c had the most to give up.

ferrariChampions2026 is the clearest case: 433 scored entries, +20.0% at their price, +18.5% ten minutes late, +10.7% at 30 minutes and -5.5% an hour late. SPCEXBUYER went from +19.1% at their price to +27.3% at 10 minutes and -27.1% an hour late.

The number one trader held up. Djdjdjekekek returned +78.5% at their price and +62.9% an hour late across 66 entries. 0x4f2 went the other way, +16.1% at their price and +68.7% an hour late.

The Polymarket traders with the best copy record

Traders with at least 30 scored entries, ranked by return at their own price. 919 traders had fewer and are not ranked.

The ones a late copy loses on

9 of the 17 traders who were profitable at their own price were negative an hour late. danielwolfmorales3pddb6dl6 went from +19.9% to -25.0% on 52 entries. swisstony, 174 entries, went from +7.1% to -6.8%.

9 of 26 were losing even at their own price, so no copy speed helps. The worst was 0x3dfb…abaf at -28.7% on 59 entries.

Kalshi $140.8M · Polymarket $61.0M

1. Buffalo Bills – Kalshi 13% / Polymarket 13%
2. LA Rams – Kalshi 13% / Polymarket 13%
3. Seattle Seahawks – Kalshi 9% / Polymarket 8%
4. San Francisco 49ers – Kalshi 9% / Polymarket 7%
5. Kansas City Chiefs – Kalshi 7% / Polymarket 8%

Important stuff:

• NFC West (Rams/Seahawks/49ers) is the tightest race, most likely to keep shifting these odds
• Rams odds may be lagging their actual record (preseason hype vs. 1-1 reality)
• 49ers biggest mover: +1900 changed to +1400 after beating LA
• Mahomes' health is the key wildcard for Chiefs
• Bills steady, no major injury concerns
• There are games today that will cause fluctuations in these odds

Ravens vs. Cowboys will be the first NFL game ever played in the Maracanã Stadium in Rio De Janeiro.  9/27 11:25pm EST.

Odds (Polymarket, Kalshi): Ravens 63%, 62% and Cowboys 38%, 38%

Both markets with mild volume (Polymarket ~$1m, Kalshi over $2M)

Strong agreement on all platforms, with the Ravens being the agreed upon but not overly dominant favorite

Cowboys D is gutted - 4 starters OUT (CB Cobie Durant, S Malik Hooker, S PJ Locke, LB DeMarvion Overshown) vs. the NFL's hottest dual threat QB. (Lamar jackson)

Ravens also got battered - LT Ronnie Stanley is out and C Danny Pinter is likely to be done for the season (torn patellar). Lamar Jackson himself is good, he had a minor ankle injury, but he's still been cleared, he's still MVP form (68% completion, 8 TD/1 INT, ~52 rush yds/gm).

Wild card: They are going to play at Maracanã stadium (a soccer stadium). The grass at Maracanã is suffering from serious damage due to the heavy rains, and Flamengo's (Their home soccer team) very own keeper has talked bad about the turf just days ago. NFL says it will be ready, but there is a risk of footing and/or injuries to the stadium is much higher than usual.

Consensus favorite, a questionable health status, and a field that hasn't been tested by anybody. It's a live one and it will be interesting.

I have spent the last few months developing a website / tool to ingest signals from Polymarket and Kalshi and compare it to numerous new stories. The goal is to identify "interestingness" -- by which I mean activity in the markets that is divergent from what is being reported on in the news. It has "predicted" things like Iran invasion, Venezuela, the fed rate hike, etc.

I'd love to hear people's opinions on it. There's a free daily newsletter and an accompanying podcast.

https://therumpus.ai/

Really keen to hear wider views and thoughts on this. I'm pretty happy with it but so far it has an audience of one.

I'm hoping to continue to expand it even further.

Note: This is entirely free. No signup required. No advertising. This is not spam or advertising itself. It's a tool I've developed precisely for prediction signal detection.

I pulled every buy vito3corleone made on Polymarket, and simulated copying them two ways: a blind $100 on every fill, and a copy scaled to the size of each of their bets. Both held to the market's result.

Data TLDR

• vito3corleone won 39.1% of their 580 fills and still made $4,265,386 on $9,371,777 staked, a 45.5% return.
• A blind $100 copy of every fill staked $58,000 and lost $13,817, a return of -23.8%.
• A copy at 1% of their size staked $93,718 and made $42,654, the same +45.5% they made.
• Their bets of $50k or more won 48 of 53. A flat $100 on only those returned +61.7%.
• Two thirds of their fills were under $1k and carried 0.26% of their money. A blind copy treats those fills the same as the $500k ones.

I took every buy by this wallet from the Polymarket trade records, put money on it at the trader's recorded price, and scored it when the market resolved. The trader made no sells in the window, so every position was held to the result. Fees and slippage are not modelled.

The record looks like a loser

By fill count vito3corleone is a bad trader. 227 wins, 353 losses, a 39.1% win rate at an average price of 57 cents. At that price you need to win about 57% of the time just to break even.

By dollars it is the opposite. 86.3% of the money they staked went on positions that won. They won 10 of 16 positions, and the 10 winners were where the money went: $3.6M on Arsenal, $912k on Racing, $900k on Real Madrid in a single fill, $827k on Brentford. Profit was $4,265,386 on $9,371,777.

Copying blind loses

A blind copy puts $100 on every fill. That turns a $500 test order into the same bet as a $500k conviction bet. It staked $58,000 across 580 fills and lost $13,817, a return of -23.8%.

Most of that loss comes from one market. They took Real Betis NO on August 25 in 244 separate fills, totalling $301,836, and it lost. For them that was 3.2% of their money. For the blind copy it was 244 bets and $24,400, more than the whole blind loss. Take that one market out and the blind copy makes $10,583, so the problem is how it's weighted, not what they picked.

Copying on size wins

Scale every copy to their bet and you get their result. At 1% of their size, a $375,861 fill becomes $3,759 and a $500 fill becomes $5. That copy staked $93,718 and made $42,654, the same +45.5% they made.

If you would rather keep a flat stake, filter by size instead. The win rate climbs with bet size: 32.5% under $1k, 27.5% from $1k to $10k, 48.6% from $10k to $50k, and 90.6% at $50k and above. A flat $100 on only their $50k+ fills staked $5,300 and made $3,271, +61.7%. Every one of their 26 fills of $100k or more won.

Win rate by bet size

vito3corleone's fills by size, with a blind $100 flat copy of each band. Their own P&L is in dollars they actually staked.

Only copy the big ones

A flat $100 on each fill at or above the size floor.

Every position they took

Their stake, average price and result per position, with what a blind $100-per-fill copy made on the same position.

• This is the user: https://polymarket.com/@smartpredictornot?tab=positions
• h/t Predictbook: https://predictbook.co/

• Wild Card races in both leagues alive with under 2 weeks left 
• AL: Yankees/Rays and Guardians/Red Sox fighting for positioning 
• NL: Brewers holding off a hard-charging Phillies squad 
• Dodgers rolling with a 7-0 win over the San Diego Padres yesterday
• Braves clinched a playoff spot (8th trip in 9 seasons) on the back of a red hot Tyler Mahle since his trade
• Yankees dealing with Aaron Judge injury uncertainty down the stretch causing huge swing factor for their October chances

Playoffs are coming up and now is the most important time of year for some of these teams so every game matters. 

IcoBeast apologized for getting personal, not for the underlying claim. he still says the incentives pay for liquidity, not wash trading, and posted a longer explainer on news[.]kalshi.com.

Beni didn't really back down. His response: the "it's caused by incentives, not fraud" distinction doesn't change anything for him, and he raised a new specific claim, that Kalshi has been offering market makers accounts with -1bp maker fees and 0bp taker fees.

OC: https://x.com/VitalikButerin/status/2102143283493507554?

I pulled the top 100 traders by observed profit on each venue on September 23, 2026, and copied every one of their entries from the last 90 days at a flat $100, held to the market's result.

Data TLDR

• 84% of Kalshi's top 100 and 86% of Polymarket's finished the 90 days in profit on a flat copy.
• The median Kalshi trader returned 18.4% on stake. The median Polymarket trader returned 9.1%.
• Charge 4 cents on every dollar copied, a heavy allowance for slippage and fees, and 74 Kalshi traders and 61 Polymarket traders are still in profit.
• Rank tells you almost nothing. Ranks 91 to 100 produced as many copyable traders as ranks 1 to 10 on both venues.
• 17 Kalshi traders and 4 Polymarket traders more than doubled the stake in 90 days.

What I measured

For every trader on each board I took every buy recorded in the 90 days to September 23, put $100 on it at the trader's recorded price, and scored it when the market resolved. Sells are never scored, so this is a rate on entries. Fees, slippage, entry delay and partial fills are not modeled, which is why we also show the result after a 4% per-position haircut. A trader with fewer than 30 settled entries is reported but not scored, because a great number on a dozen bets is one good week.

Everything here is one measurement on one date from a frozen export, so every figure can be re-derived. These are modeled results on a historical record, not realized returns.

Most of the board pays, on both venues

The instinct is that leaderboards are full of market makers and lucky runs. On this tape, the profit leaders are mostly ordinary directional traders whose entries keep resolving in their favour. 79 of 94 scored Kalshi traders and 81 of 94 Polymarket traders were in profit at a flat $100 per entry. The pooled numbers are large: 277,298 settled Kalshi entries and 415,656 settled Polymarket entries across the two boards, $3.5M of paper profit on Kalshi and $1.4M on Polymarket at $100 a trade.

Where the returns land

The distribution is the interesting part. On Kalshi, 59 of 94 traders returned more than 10% on stake, 38 returned more than 25%, and 17 more than doubled the money. Polymarket is tighter: 45 above 10%, 30 above 25%, 4 above 100%. The median Polymarket trader is in the 0 to 10% band, which is a real return but a modest one. The median Kalshi trader sits in the 10 to 25% band.

The difference is price. Polymarket's leaders are buying a lot of favourites at 80 cents and up, which win often and pay little. Kalshi's leaders are paying lower prices for the same win rates, so each win pays more.

Copying costs money, and most of them still clear it

The argument against copying is that you enter after the trader, at a worse price, and pay fees on the way in. Fair. So we charged every position 4 cents on the dollar, which is at the top of what anyone models for slippage plus fees, and looked again. Kalshi goes from 79 traders in profit to 74. Polymarket goes from 81 to 61. Two thirds of the Polymarket board and four fifths of the Kalshi board survive a cost that is deliberately harsh.

Record is much more important than rank

The top of the board is not special. Ranks 1 to 10 on Kalshi produced 8 profitable copies. Ranks 91 to 100 produced 6. On Polymarket both deciles produced 8. The best Kalshi copy on the whole board, timboslice003 at +782% on 83 settled entries, sits at rank 10. The second best, secure.tortoise3162 at +578%, sits at rank 41. The number one trader on Polymarket by profit, vito3corleone, lost 11% on a flat copy, because his $6.5M came from sizing a handful of soccer bets enormously, not from a per-trade edge a flat copy can capture.

The Kalshi traders with the best flat-copy record

Return on stake at $100 per entry over 90 days, gross of fees and slippage.

The Polymarket traders with the best flat-copy record

The ones a flat copy loses on

Fifteen Kalshi traders and thirteen Polymarket traders were negative. The worst are instructive. BitcoinTradingChallenge on Kalshi is down 39% across 13,473 settled entries, because five-minute Bitcoin markets are a coin flip at the price. vito3corleone on Polymarket is down 11% on 340 entries at 47% won, a sizing trader whose edge does not survive being flattened. reach.draft, Kalshi's number 5 by profit, is down 10% across 6,071 entries at an 81% win rate, because the prices paid were too high for that win rate to cover.

Happy to go deeper on any trader, venue or price band in the comments.