Reversal Index
When large wallets pile into one side of a Polymarket contract, does the market move their way? This page records those positions before the outcome is known, and scores them against the probability the market itself was quoting at the moment the money went in.
That last part is the whole point. A hit rate on its own says nothing: if whales bought at 60¢, the market was already calling it a 60% shot, and being right 60% of the time is not insight — it is the price. The only number worth reporting is the margin over the market, with the error bars attached.
Live ledger — positions recorded in advance
Too few graded positions to mean anything yet. This section will not be presented as a finding until at least 30 have resolved and the result survives a significance test.
| Market | Whales backed | Market said | Outcome |
|---|---|---|---|
| Will there be no change in Fed interest rates after the July 2026 meeting? recorded 2026-07-27 · 25 wallets · $1.3M | Yes | 83¢ | open |
| San Diego Padres vs. Atlanta Braves recorded 2026-07-27 · 5 wallets · $136k | Atlanta Braves | 70¢ | open |
| UFC Freedom 250: Ciryl Gane vs. Alex Pereira (Heavyweight, Main Card) recorded 2026-07-27 · 3 wallets · $130k | Alex Pereira | 52¢ | open |
| Houston Astros vs. Chicago White Sox recorded 2026-07-27 · 3 wallets · $130k | Chicago White Sox | 51¢ | open |
| LoL: Top Esports vs ThunderTalk Gaming (BO3) - LPL Group Ascend recorded 2026-07-27 · 6 wallets · $127k | Top Esports | 71¢ | open |
| LoL: ThunderTalk Gaming vs EDward Gaming - Game 2 Winner recorded 2026-07-27 · 3 wallets · $116k | ThunderTalk Gaming | 55¢ | open |
The baseline, and why it proves nothing
Before committing to anything forward-looking we scored 83 positions that had already resolved. Whale-backed outcomes landed 66% of the time. The market was quoting 59% when they bought. That is an edge of 7.1 points — about 6 extra wins over 83 bets.
A 66% hit rate reads well, and it would be easy to put it on a chart and stop there. It does not hold up. The 95% confidence interval runs from 56% to 76%, and the market's own 59% sits inside it. At p = 0.16, chance explains the gap comfortably.
This is the question our first backtest could not answer: back then only three markets were both genuinely contested and heavily whale-funded, which is no sample at all. It is 83 now, and the answer is still the same one.
There is a second, worse problem. We chose the selection bars after looking at this data. Criteria fitted to a sample will always flatter it, so no backtest run this way can settle the question, however large it gets. That is the reason the live ledger exists at all — it is the same measurement with the fitting removed.
All 85 baseline positions
| Market | Whales backed | Market said | Outcome |
|---|---|---|---|
| Will Spain win the 2026 FIFA World Cup? recorded 2026-07-21 · 48 wallets · $2.9M | Yes | 59¢ | right |
| Will Argentina win the 2026 FIFA World Cup? recorded 2026-07-21 · 24 wallets · $1.5M | Yes | 32¢ | wrong |
| Will France win on 2026-07-18? recorded 2026-07-21 · 20 wallets · $1.3M | Yes | 53¢ | wrong |
| Will United States win on 2026-07-06? recorded 2026-07-21 · 5 wallets · $1.1M | No | 64¢ | right |
| Spurs vs. Knicks recorded 2026-07-21 · 3 wallets · $936k | Spurs | 47¢ | right |
| Will Morocco win on 2026-06-24? recorded 2026-07-21 · 6 wallets · $910k | Yes | 65¢ | right |
| Spread: France (-2.5) recorded 2026-07-21 · 3 wallets · $809k | Iraq | 43¢ | wrong |
| Will Japan win on 2026-06-25? recorded 2026-07-21 · 7 wallets · $777k | No | 59¢ | right |
| Will France win on 2026-07-14? recorded 2026-07-21 · 6 wallets · $774k | No | 63¢ | right |
| Will Spain win on 2026-07-19? recorded 2026-07-21 · 9 wallets · $719k | No | 58¢ | right |
| Will France win on 2026-07-09? recorded 2026-07-21 · 13 wallets · $638k | Yes | 69¢ | right |
| Will Argentina win on 2026-06-22? recorded 2026-07-21 · 7 wallets · $613k | Yes | 71¢ | right |
| France vs. England: Team to Win recorded 2026-07-21 · 19 wallets · $557k | France | 64¢ | wrong |
| Will Spain vs. Argentina end in a draw? recorded 2026-07-21 · 8 wallets · $535k | Yes | 36¢ | right |
| France vs. Spain: Team to Advance recorded 2026-07-21 · 7 wallets · $522k | Spain | 43¢ | right |
| Will Argentina win on 2026-07-19? recorded 2026-07-21 · 12 wallets · $522k | No | 74¢ | right |
| Will Argentina win on 2026-07-03? recorded 2026-07-21 · 9 wallets · $521k | No | 73¢ | right |
| England vs. Argentina: Team to Advance recorded 2026-07-21 · 9 wallets · $518k | Argentina | 49¢ | right |
| Mexico vs. Ecuador: Team to Advance recorded 2026-07-21 · 4 wallets · $509k | Mexico | 63¢ | right |
| Will Japan win on 2026-06-21? recorded 2026-07-21 · 3 wallets · $505k | Yes | 70¢ | right |
| Will Morocco win on 2026-06-19? recorded 2026-07-21 · 6 wallets · $484k | No | 41¢ | wrong |
| Will United States win on 2026-06-12? recorded 2026-07-21 · 9 wallets · $483k | Yes | 63¢ | right |
| Will Belgium win on 2026-06-21? recorded 2026-07-21 · 6 wallets · $451k | Yes | 64¢ | open |
| UFC Fight Night: Kamaru Usman vs. Dricus Du Plessis (Middleweight, Main Card) recorded 2026-07-21 · 9 wallets · $445k | Dricus Du Plessis | 67¢ | right |
| Will France win the 2026 FIFA World Cup? recorded 2026-07-21 · 15 wallets · $442k | Yes | 27¢ | wrong |
| Will Germany win on 2026-06-20? recorded 2026-07-21 · 13 wallets · $441k | Yes | 71¢ | right |
| Will Netherlands win on 2026-06-20? recorded 2026-07-21 · 5 wallets · $410k | Yes | 63¢ | right |
| Will Croatia win on 2026-06-23? recorded 2026-07-21 · 3 wallets · $403k | Yes | 84¢ | right |
| Will England win on 2026-07-18? recorded 2026-07-21 · 13 wallets · $371k | Yes | 60¢ | right |
| Will Scotland win on 2026-06-13? recorded 2026-07-21 · 9 wallets · $366k | No | 37¢ | wrong |
| Will Belgium win on 2026-06-15? recorded 2026-07-21 · 3 wallets · $352k | Yes | 66¢ | wrong |
| Will the New York Knicks win the 2026 NBA Finals? recorded 2026-07-21 · 4 wallets · $348k | Yes | 80¢ | right |
| Will Croatia win on 2026-06-27? recorded 2026-07-21 · 5 wallets · $328k | Yes | 57¢ | right |
| Mexico vs. England: Team to Advance recorded 2026-07-21 · 11 wallets · $315k | England | 56¢ | right |
| Portugal vs. Spain: O/U 2.5 recorded 2026-07-21 · 3 wallets · $311k | Over | 55¢ | wrong |
| Spread: Spain (-1.5) recorded 2026-07-21 · 6 wallets · $306k | Argentina | 80¢ | right |
| Australia vs. Egypt: Team to Advance recorded 2026-07-21 · 4 wallets · $306k | Australia | 44¢ | wrong |
| Will France win on 2026-07-04? recorded 2026-07-21 · 10 wallets · $302k | Yes | 83¢ | right |
| Spread: England (-2.5) recorded 2026-07-21 · 5 wallets · $298k | Panama | 55¢ | right |
| Will Egypt win on 2026-06-21? recorded 2026-07-21 · 5 wallets · $282k | No | 45¢ | wrong |
| Will IR Iran win on 2026-06-15? recorded 2026-07-21 · 5 wallets · $281k | Yes | 54¢ | wrong |
| Will England win on 2026-07-15? recorded 2026-07-21 · 4 wallets · $280k | Yes | 40¢ | wrong |
| France vs. Morocco: Team to Advance recorded 2026-07-21 · 5 wallets · $241k | France | 78¢ | right |
| France vs. England: O/U 3.5 recorded 2026-07-21 · 5 wallets · $217k | Over | 45¢ | right |
| Spain vs. Cabo Verde: O/U 3.5 recorded 2026-07-21 · 3 wallets · $210k | Under | 47¢ | right |
| Will France win on 2026-06-30? recorded 2026-07-21 · 5 wallets · $206k | No | 23¢ | wrong |
| Will Norway win on 2026-06-22? recorded 2026-07-21 · 6 wallets · $206k | Yes | 82¢ | right |
| Will Colombia win on 2026-07-07? recorded 2026-07-21 · 5 wallets · $203k | No | 59¢ | right |
| Spain vs. Argentina: O/U 1.5 recorded 2026-07-21 · 7 wallets · $198k | Over | 65¢ | wrong |
| France vs. England: Both Teams to Score recorded 2026-07-21 · 8 wallets · $197k | No | 32¢ | wrong |
| Will Brazil win on 2026-07-05? recorded 2026-07-21 · 5 wallets · $197k | Yes | 54¢ | wrong |
| Portugal vs. Spain: Team to Advance recorded 2026-07-21 · 4 wallets · $179k | Spain | 67¢ | right |
| Spurs vs. Knicks recorded 2026-07-21 · 5 wallets · $171k | Spurs | 77¢ | wrong |
| Argentina vs. Egypt: Team to Advance recorded 2026-07-21 · 5 wallets · $171k | Argentina | 83¢ | right |
| LoL: T1 vs Gen.G (BO3) - Esports World Cup Playoffs recorded 2026-07-21 · 8 wallets · $169k | Gen.G | 67¢ | right |
| LoL: T1 vs Karmine Corp - Game 1 Winner recorded 2026-07-21 · 3 wallets · $163k | T1 | 74¢ | right |
| LoL: T1 vs Gen.G - Game 1 Winner recorded 2026-07-21 · 7 wallets · $160k | Gen.G | 84¢ | right |
| United States vs. Belgium: Team to Advance recorded 2026-07-21 · 4 wallets · $159k | United States | 54¢ | wrong |
| Will Mexico win on 2026-06-18? recorded 2026-07-21 · 7 wallets · $154k | Yes | 55¢ | right |
| Knicks vs. Spurs recorded 2026-07-21 · 4 wallets · $153k | Knicks | 33¢ | right |
| Will Germany win on 2026-06-29? recorded 2026-07-21 · 3 wallets · $145k | Yes | 74¢ | wrong |
| Mexico vs. Korea Republic: O/U 2.5 recorded 2026-07-21 · 4 wallets · $139k | Under | 57¢ | right |
| Will Senegal win on 2026-06-22? recorded 2026-07-21 · 4 wallets · $136k | No | 82¢ | right |
| Will England win on 2026-06-23? recorded 2026-07-21 · 4 wallets · $135k | Yes | 81¢ | wrong |
| Will Mexico win on 2026-07-05? recorded 2026-07-21 · 4 wallets · $129k | No | 85¢ | right |
| UFC Fight Night: Chase Hooper vs. Mitch Ramirez (Lightweight, Main Card) recorded 2026-07-21 · 3 wallets · $126k | Mitch Ramirez | 24¢ | wrong |
| Will Portugal win on 2026-07-02? recorded 2026-07-21 · 5 wallets · $125k | Yes | 57¢ | right |
| Will Spain win on 2026-07-14? recorded 2026-07-21 · 5 wallets · $125k | Yes | 53¢ | right |
| Exact Score: Spain 0 - 0 Argentina? recorded 2026-07-21 · 3 wallets · $125k | Yes | 20¢ | right |
| Will United States win on 2026-07-01? recorded 2026-07-21 · 3 wallets · $123k | Yes | 74¢ | right |
| Spread: Germany (-1.5) recorded 2026-07-21 · 3 wallets · $120k | Germany | 48¢ | wrong |
| Spread: England (-1.5) recorded 2026-07-21 · 3 wallets · $120k | England | 59¢ | wrong |
| Will Türkiye win on 2026-06-25? recorded 2026-07-21 · 3 wallets · $118k | Yes | 28¢ | right |
| UFC Freedom 250: Justin Gaethje vs. Ilia Topuria (Lightweight, Main Card) recorded 2026-07-21 · 4 wallets · $118k | Ilia Topuria | 79¢ | wrong |
| Will Brazil win on 2026-06-13? recorded 2026-07-21 · 5 wallets · $117k | No | 66¢ | right |
| Los Angeles Dodgers vs. New York Yankees recorded 2026-07-21 · 5 wallets · $116k | Los Angeles Dodgers | 63¢ | right |
| Iran agrees to end enrichment of uranium by June 30? recorded 2026-07-21 · 3 wallets · $113k | No | 72¢ | right |
| Will Switzerland win on 2026-07-02? recorded 2026-07-21 · 5 wallets · $112k | Yes | 72¢ | right |
| Will Croatia win on 2026-06-17? recorded 2026-07-21 · 4 wallets · $111k | No | 84¢ | right |
| Will Uruguay win on 2026-06-21? recorded 2026-07-21 · 4 wallets · $110k | Yes | 67¢ | wrong |
| Athens Open: Tereza Valentova vs Alina Korneeva recorded 2026-07-21 · 3 wallets · $108k | Tereza Valentova | 64¢ | wrong |
| Will Switzerland vs. Colombia end in a draw? recorded 2026-07-21 · 3 wallets · $108k | Yes | 34¢ | right |
| France vs. Iraq: 1st Half O/U 1.5 recorded 2026-07-21 · 3 wallets · $107k | Over | 55¢ | wrong |
| Will DR Congo win on 2026-06-27? recorded 2026-07-21 · 4 wallets · $102k | Yes | 58¢ | right |
| Will United States win on 2026-06-25? recorded 2026-07-21 · 5 wallets · $101k | No | 56¢ | open |
Method
- What counts as whale flow. Individual fills of $10k or more, from the on-chain trade tape.
- What makes a position. A market needs at least $100k of such fills across 3 or more wallets, with at least 65% of bought notional on one side.
- It has to be a real call. The notional-weighted entry price must sit between 15¢ and 85¢. Buying at 97¢ is not a prediction, and including it would inflate the hit rate without adding information.
- Grading. We have no official resolution feed, so a position is scored when one outcome's last print reaches 97¢. Markets that go quiet below that stay open instead of being scored against whichever side happened to be ahead. This is a proxy for resolution, not an oracle.
- Nothing is revised. Once recorded, a position's market, side, entry price and date are frozen; the only fields that can ever change are the outcome and the date it landed.
- What this is not. Not profit and loss — it ignores position sizing, fees and exits. Not advice. Wallets are identified by address only; no attempt is made to say who is behind one.
Data as of 2026-07-27. Related: whale activity by market · whale index