Joshua Della Vedova

Updated 2026-W36 · week of 2026-08-31

Della Vedova Prediction Market Indices

Traders moved $470 million through Polymarket in the week of 2026-08-31, across 17.0 million individual trades. Algorithmic wallets accounted for 66% of weekly counterparty events (both maker and taker sides counted); everyone else split the remaining 34%. The most-traded market was "Will the U.S. invade Iran before 2027?", pulling in $892K of volume.

Cumulative since November 2022: +$140M to algorithmic wallets · -$81M from active retail.

Cumulative P&L by trader type, Polymarket since November 2022 Bots have captured +$140M; active retail traders are down -$81M. Zero-sum market: bot gains and retail losses balance to within fees and the smaller wallet types.
Cumulative resolved profit and loss by wallet type since 2022 Line chart of running-sum P&L per wallet type. Bots accumulate positive P&L; active retail accumulates losses. -$50M $0 +$50M +$100M +$150M 2024 2025 2026 Bots: +$140M Active retail: -$81M
Source: Della Vedova (2026), “Who Profits from Prediction? Execution, not Information” · Updated weekly · Download data

Source: Della Vedova (2026), “Who Profits from Prediction?” · Methodology · Download data · This week’s briefings

Joshua Della Vedova

Joshua Della Vedova

Associate Professor of Finance · Knauss School of Business, University of San Diego

I study why markets behave irrationally and how human psychology shapes financial decisions. My research on prediction markets uses 671M on-chain Polymarket records (222M resolved trades) to measure who trades, who profits, and where private information appears. The dashboard makes that work continuously visible.

Open to collaboration. I share the full trade-level dataset with academic researchers and welcome coauthorship proposals from PhD students and faculty working on prediction-market questions. I also provide referee-style comments on prediction-market papers in progress. Reach out by email.

Consulting & expert testimony. Available for litigation, regulatory, and compliance engagements involving prediction-market microstructure and informed-trading detection. Schedule a 15-minute intro call →

This week on Polymarket
$892K on the biggest market · 6 briefings ready to read
View all 6 briefings →
671M on-chain records
222M resolved trades (study sample)
+$133M bot profits (study sample)
−$79M retail losses (study sample)

Who makes money — and why

Retail traders pick winners more often than bots. They still lose. The gap is timing, not information. Read the paper →

ALGORITHMIC SHARE OF TRADING
80%
Algorithmic wallets account for 80% of all trades (13-week moving average), up from near zero in late 2022. They earn the only positive aggregate return despite coin-flip directional accuracy (49.9%).
Read more →
WHO WON THIS WEEK
unclassified
unclassified wallets cleared +$93K of resolved P&L in week 2026-W36.
Read more →
Top 30 Polymarket markets, week of 2026-W36 Rectangle area = weekly USD volume. Color = market category. Hover for full market name.
Top Polymarket markets by weekly volume Treemap of the top 30 markets this week. Cell area is proportional to USD volume; cell color encodes market category. Will the U.S. invade Iran before 2027? Volume: $892K · Trades: 2,963 Implied: 14% YES Algorithmic share: 66% Category: Geopolitics Will the U.S. invadeIran before 2027? 14% YES $892K vol Clarity Act signed into law in 2026? Volume: $550K · Trades: 1,706 Implied: 17% YES Algorithmic share: 58% Category: Other Clarity Act signed intolaw in 2026? 17% YES $550K vol Will Carlos Alcaraz win the 2026 Men's US Open? Volume: $486K · Trades: 4,045 Implied: 56% YES Algorithmic share: 71% Category: Other Will Carlos Alcaraz winthe 2026 Men's US Open? 56% YES $486K vol Will Renan Santos win the 2026 Brazilian presidential election? Volume: $453K · Trades: 2,834 Implied: 2% YES Algorithmic share: 46% Category: Politics Will Renan Santos winthe 2026 Brazilianpresidential election? 2% YES $453K vol Will China invade Taiwan by end of 2026? Volume: $441K · Trades: 893 Implied: 4% YES Algorithmic share: 48% Category: Geopolitics Will China invade Taiwanby end of 2026? 4% YES $441K vol Will United Russia (ER) gain the most seats in the next Russian parliamentary election? Volume: $390K · Trades: 2,430 Implied: 69% YES Algorithmic share: 57% Category: Geopolitics Will United Russia(ER) gain the mostseats in the nextRussian parliamentary… 69% YES $390K vol Fed rate hike in 2026? Volume: $254K · Trades: 1,471 Implied: 71% YES Algorithmic share: 58% Category: Macro Fed rate hikein 2026? 71% YES $254K vol Will the Iranian regime fall before 2027? Volume: $228K · Trades: 805 Implied: 7% YES Algorithmic share: 69% Category: Other Will theIranianregime fall… 7% YES $228K vol Will Flávio Bolsonaro win the 2026 Brazilian presidential election? Volume: $216K · Trades: 2,087 Implied: 40% YES Algorithmic share: 61% Category: Politics Will FlávioBolsonarowin the 2026… 40% YES $216K vol Will Bitcoin dip to $45,000 by December 31, 2026? Volume: $186K · Trades: 491 Implied: 10% YES Algorithmic share: 66% Category: Crypto Will Bitcoindip to $45,000by December… 10% YES $186K vol Will Bitcoin dip to $35,000 by December 31, 2026? Volume: $183K · Trades: 207 Implied: 6% YES Algorithmic share: 61% Category: Crypto Will Bitcoindip to $35,000by December… 6% YES $183K vol Trump out as President before 2027? Volume: $175K · Trades: 483 Implied: 6% YES Algorithmic share: 50% Category: Politics Trump out asPresidentbefore 2027? 6% YES $175K vol Will Luiz Inácio Lula da Silva win the 2026 Brazilian presidential election? Volume: $174K · Trades: 1,213 Implied: 57% YES Algorithmic share: 60% Category: Politics Will LuizInácio Lulada Silva win… 57% YES $174K vol Will Alexander Zverev win the 2026 Men's US Open? Volume: $167K · Trades: 1,901 Implied: 23% YES Algorithmic share: 68% Category: Other WillAlexanderZverev win… 23% YES $167K vol Will the US confirm that aliens exist before 2027? Volume: $138K · Trades: 759 Implied: 4% YES Algorithmic share: 41% Category: Other Will the USconfirm thataliens exist… 4% YES $138K vol Will no Fed rate cuts happen in 2026? Volume: $130K · Trades: 1,485 Implied: 93% YES Algorithmic share: 61% Category: Macro Will no Fedrate cutshappen in… 93% YES $130K vol Will Daniil Medvedev win the 2026 Men's US Open? Volume: $119K · Trades: 1,975 Implied: 0% YES Algorithmic share: 76% Category: Other Will DaniilMedvedevwin the… 0% YES $119K vol Xi Jinping out before 2027? Volume: $115K · Trades: 841 Implied: 4% YES Algorithmic share: 51% Category: Other Xi Jinpingout before2027? 4% YES $115K vol Will New People (NL) gain the most seats in the next Russian parliamentary election? Volume: $111K · Trades: 1,610 Implied: 25% YES Algorithmic share: 62% Category: Politics Will NewPeople(NL) gain… 25% YES $111K vol Will JD Vance win the 2028 US Presidential Election? Volume: $105K · Trades: 689 Implied: 25% YES Algorithmic share: 42% Category: Politics Will JDVance winthe 2028… 25% YES $105K vol 2026 Balance of Power: R Senate, R House Volume: $95K · Trades: 606 Implied: 12% YES Algorithmic share: 55% Category: Politics 2026Balance of… 12% YES $95K vol Friedrich Merz out as Chancellor of Germany before 2027? Volume: $90K · Trades: 440 Implied: 14% YES Algorithmic share: 63% Category: Politics FriedrichMerz out asChancellor… 14% YES $90K vol Will Kimi Antonelli be the 2026 F1 Drivers' Champion? Volume: $88K · Trades: 1,054 Implied: 85% YES Algorithmic share: 73% Category: Sports Will KimiAntonellibe the… 85% YES $88K vol Will Bitcoin reach $100,000 by December 31, 2026? Volume: $85K · Trades: 383 Implied: 25% YES Algorithmic share: 67% Category: Crypto WillBitcoinreach… 25% YES $85K vol Will 1 Fed rate cut happen in 2026? Volume: $82K · Trades: 1,139 Implied: 5% YES Algorithmic share: 60% Category: Macro Will 1 Fedrate cuthappen in… 5% YES $82K vol Will Magdalena Andersson be the next Prime Minister of Sweden? Volume: $81K · Trades: 1,457 Implied: 78% YES Algorithmic share: 66% Category: Politics WillMagdalenaAndersson… 78% YES $81K vol Will GPT-6 be released by December 31, 2026? Volume: $79K · Trades: 892 Implied: 100% YES Algorithmic share: 69% Category: Other Will GPT-6bereleased… 100% YES $79K vol Will Benjamin Netanyahu be the next Prime Minister of Israel? Volume: $77K · Trades: 732 Implied: 30% YES Algorithmic share: 53% Category: Geopolitics WillBenjaminNetanyahu… 30% YES $77K vol Will Ben Shelton win the 2026 Men's US Open? Volume: $74K · Trades: 1,850 Implied: 9% YES Algorithmic share: 76% Category: Other Will BenSheltonwin the… 9% YES $74K vol Will Taylor Fritz win the 2026 Men's US Open? Volume: $71K · Trades: 1,194 Implied: 0% YES Algorithmic share: 70% Category: Other WillTaylorFritz win… 0% YES $71K vol
Color = category
Geopolitics Other Politics Macro / Finance Crypto Sports

Detecting informed trading

A per-event test separates episodic private information from sustained skill. Zero false positives on a real-data placebo. See all six surveillance indices →

SUSTAINED-ACCURACY OUTLIERS (SKILL, NOT NECESSARILY INFORMATION)
10,485
Of 705,883 wallets tested, 10,485 (1.49%) show anomalous long-run accuracy. The June 2026 paper shows this wallet-level statistic measures sustained skill; episodic information requires the per-event test.
Read more →
PER-EVENT DETECTION FUNNEL
11
Raw flags 1,008
Defensible 257
Core 112
Survive 5% 11
From 1,008 raw event-level flags, excluding mutually exclusive and dependent bet structures leaves a 112-pair core; 11 trader-event pairs survive the dependence adjustment at the 5% level. Zero discoveries on the placebo class.
Read more →

Six live DV-PMI Surveillance Indices cover the full market integrity picture: informed trading, insider timing, adverse selection, resolution surprise, wash trading, and concentration risk.

How traders price uncertainty

Human traders systematically overestimate long shots and underestimate near-certainties — even in liquid prediction markets. See the calibration data →

PROBABILITY WEIGHTING INDEX
α = 0.664
Traders overweight low-probability outcomes and underweight high-probability ones. The current Prelec parameter of 0.664 is near the classic Kahneman-Tversky experimental value of 0.65 — a behavioral pattern this liquid market has not arbitraged away.
Read more →
MARKET CALIBRATION
R² = 0.987
How well do Polymarket prices predict actual outcomes? Realized win rates match prices closely overall, but long shots win less often than priced and near-certainties win more.
Read more →
Press mentions
Recent coverage of the research in news and media
  1. Jul 23, 2026 PRESS
    Bloomberg Businessweek's Big Take quotes Della Vedova on where insider trading concentrates

    Denitsa Tsekova and Leonardo Nicoletti analyze 34,000 Polymarket trades flagged as potential insider activity: roughly $200 million in flagged volume from January through June 2026, driven by bets on military action in Iran and Venezuela. Winnings were heavily concentrated, with the top 1% of profitable wallets capturing more than half the money; 57% of those wallets were created less than 24 hours before trading. The piece quotes our assessment of where private-information trading concentrates: elections, committee decisions, award shows, ballot measures, and government votes, the markets where a small group knows the outcome first. Their category-level findings match that ordering; financial and economic markets showed the least flagged activity.

    Read the Big Take →
  2. Jul 23, 2026 PRESS
    The Atlantic quotes Della Vedova on 'outsider trading' after the Paris hair-dryer incident

    Kaitlyn Tiffany's July 20 piece examines a new class of prediction-market conduct: winning a bet by changing the world instead of forecasting it. In April a Météo-France sensor near Charles de Gaulle jumped 4 degrees Celsius in twelve minutes; a wallet positioned above the 21-degree strike against an 18-degree consensus collected roughly $20,000, and Météo-France filed a criminal complaint. Polymarket changed its data source but let the winnings stand; France ordered internet providers to block the site on July 16. The article quotes our recommendations: screen for excess accuracy (a wallet betting one song hits No. 1 while betting no on every rival shows confidence the market's prices cannot explain, whether it comes from an inside line or rigged streams), limit bet sizes where results are cheap to rig, and never resolve a market from a single number at a single source. The trader who rigs the sensor never out-forecasts anyone; the same trade-record footprint our insider-timing and resolution-surprise indices flag gives them away.

    Read the article →
  3. Jun 17, 2026 PRESS
    Bloomberg: Polymarket bets on Iran deal fuel fresh insider-trading fears

    Bloomberg cited Josh's research on informed trading in a feature on suspicious Polymarket activity tied to the US-Iran conflict. The article identifies $45 million in flagged trades on Iran-related markets and profiles wallets that bet on a peace deal at 6% odds before the announcement. Quote: "In the political markets, there's constantly information being created. In a market in which you have a small amount of decision makers, information is likely to be able to be leaked out."

    Read on Bloomberg →
  4. May 1, 2026 PRESS
    On CNBC: bots are outperforming traders in prediction markets

    Walked through the headline finding from Paper 1 and how the dashboard makes the bot-vs-retail transfer continuously visible. Watch the full segment on CNBC.com.

    Watch on CNBC →
▶ Featured video · CNBC · May 1, 2026
"Finance Professor Josh Della Vedova talks new report bots are outperforming traders in prediction markets"
Watch on CNBC.com →
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Joshua Della Vedova · Knauss School of Business, University of San Diego Updated weekly · 2026-W36
Cite this dataset Della Vedova, J. (2026). Della Vedova Prediction Market Indices (DV-PMI). https://jdellavedova.com