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Pew’s “Typical Polymarket User” Is a Sampled Active Wallet
Pew’s 2026 Polymarket study tracks selected active wallets, not all users. Here’s how event selection, multiple wallets and API limits affect the findings.
Pew Research Center’s July 22, 2026 study found that the median account made 46 trades across 10 active trading days during its six-week observation period. That is useful evidence about the wallets Pew tracked—not a representative estimate for every Polymarket user, every unique person or the newer Polymarket U.S. platform. Pew’s report and methodology make those boundaries visible.
The key sample-bias issue is how accounts entered the study: through recent trades on ten selected high-volume events, rather than through a random draw from all accounts.
What Pew actually sampled
Pew’s collection had two stages:
- Build the initial account list. In early May 2026, researchers selected ten high-volume events across several topics and collected the 4,000 most recent trades on each. Those trades identified 16,836 distinct accounts.
- Observe subsequent activity. Researchers collected activity for those accounts 15 times between May 7 and June 19. That yielded activity for 11,989 active wallets, the denominator behind the published findings.
Pew explicitly says that some individuals may operate multiple accounts and that its data source excludes Polymarket’s newer U.S. platform. Its methodology also reports that 2% of wallets reached the collection limit, potentially leaving some activity uncaptured. Source: Pew methodology.
Importantly, the ten events were entry points into the sample, not the only events studied afterward. Pew subsequently collected the selected accounts’ activity and categorized the events they traded.
Where selection can change the result
The seed events included Bitcoin price targets, a Fed chair confirmation question, several sports fixtures, an AI-model ranking and social-media posting counts. That gives the sample variety, but variety alone does not make a sample representative. The exact selection is listed in Pew’s appendix.
| Design feature | What it means for interpretation |
|---|---|
| Ten selected high-volume events | Accounts trading only elsewhere have no route into the initial sample. |
| Most recent 4,000 trades per event | Inclusion depends on trading within each event’s recent-trade window, not simply on having an account. These are trade-count windows, not a common calendar interval. |
| Activity observed for 11,989 wallets | The reported median describes the observed active subset, not all 16,836 seed accounts. |
| Wallets rather than verified people | One person can contribute multiple observations. |
| Collection limit reached by 2% | Some activity may be missing, especially relevant when examining very active accounts. |
Within a seed event, an account placing many trades has more opportunities to appear in the recent-trades window than an account trading once. Deduplicating wallet addresses prevents repeated trades from becoming repeated accounts; it does not remove that difference in opportunities for inclusion. Heavy trading outside the seed events, however, does not itself qualify an account for the sample.
This creates a plausible tilt toward active traders. But the published results do not establish how much the platform-wide median differs—or even the net direction of every reported statistic. Event selection, topic mix and subsequent inactivity can affect different measures differently. “Selection bias” here means a limit on generalization, not proof that the reported calculations are wrong.
What the API can—and cannot—tell you
The Polymarket activity API documentation identifies records by a user profile address and exposes fields including timestamps, transaction hashes, prices, assets and buy/sell sides. It also distinguishes trades from redemptions and other activity types.
Those are account-activity records, not a census of unique people. They do not, by themselves, establish demographic representativeness or whether an account’s activity is manual or automated.
Keep historical collection limits separate from current documentation. Pew reports a limit of 4,000 recent activities per account per collection during its study. As checked on October 5, 2026, the API documentation instead specifies a maximum page size of 500, offsets up to 5,000 and date-window pagination for deeper history. The current instructions should not be substituted for Pew’s account of its earlier collection.
Nor does “2% hit the limit” mean “2% of trades are missing.” It is a share of wallets, not a measured share of activity.
Does this undermine Polymarket probabilities?
Not by itself. Pew studied account behavior; it did not test whether market probabilities matched subsequent outcomes. A median trade count cannot establish either accurate forecasting or miscalibration.
That requires a different sample: defined contracts, probability snapshots taken before outcomes were known, and reliable resolution records. See Brier score versus calibration for the distinction between overall forecast error and whether, for example, events priced near 70% happen about 70% of the time.
The defensible shorthand is: “Among Pew’s 11,989 observed active wallets, the median made 46 trades from May 7 to June 19, 2026.” Dropping the sample and dates turns a bounded finding into a platform-wide claim the study design does not establish.