Polymarket Whale Tracker (2026): How to Track Big Wallets With the API

Does Polymarket have a whale tracker API?

Not as one endpoint. A whale tracker is a loop: find large trades, look up the wallets behind them, and keep watching the wallets worth following. Polymarket attributes every fill to a wallet in its public Data API at https://data-api.polymarket.com, so each step is a keyless GET request.

List endpoints return a { data, pagination } envelope and page with an opaque next_cursor. The full field reference is in our Polymarket Data API guide.

How do you find large trades on Polymarket?

Ask the trades feed for a minimum cash size. This returns the 50 most recent trades worth $10,000 or more across all of Polymarket:

curl -s "https://data-api.polymarket.com/v2/trades?filter_type=CASH&filter_amount=10000&limit=50"

In our checks, every row returned with CASH had a size times price at or above the threshold. With the default TOKENS, a 10,000-share trade priced at a tenth of a cent, worth $10, passed the same filter. Without a user, market or event filter, the feed covers a rolling window of the current and previous month, while market and event filters reach back three years.

To turn the query into a tracker, poll it and print only trades you have not seen. This runs on Node 18 or newer with no dependencies:

const BASE = 'https://data-api.polymarket.com';
const MIN_USD = 10_000;
const seen = new Set();
let baseline = true;

async function poll() {
  const url = new URL('/v2/trades', BASE);
  url.searchParams.set('filter_type', 'CASH');
  url.searchParams.set('filter_amount', String(MIN_USD));
  url.searchParams.set('limit', '100');

  const res = await fetch(url);
  if (!res.ok) throw new Error(`Data API returned ${res.status}`);
  const { data } = await res.json();

  for (const t of data.reverse()) {
    const key = `${t.transaction_hash}:${t.token_id}:${t.proxy_wallet}`;
    if (seen.has(key)) continue;
    seen.add(key);
    if (baseline) continue;
    const usd = Math.round(t.size * t.price).toLocaleString('en-US');
    console.log(`${t.side} $${usd} of "${t.outcome}" on ${t.title} by ${t.proxy_wallet}`);
  }
  baseline = false;
}

await poll();
setInterval(() => poll().catch(console.error), 60_000);

The unified TypeScript SDK exposes the same filter on listTrades:

import { createPublicClient, TradeFilterType } from '@polymarket/client';

const client = createPublicClient();
const pages = client.listTrades({ filterType: TradeFilterType.Cash, filterAmount: 10_000, pageSize: 50 });

const { items } = await pages.firstPage();
for (const trade of items) {
  const usd = Number(trade.size) * Number(trade.price);
  console.log(trade.wallet, trade.side, Math.round(usd), trade.title);
}

How do you see what a whale holds?

Pass the proxy_wallet from a trade row as user. This reads a wallet's stats card, marked portfolio value, largest open positions and first recorded action in parallel:

const BASE = 'https://data-api.polymarket.com';

async function get(path, params) {
  const url = new URL(path, BASE);
  for (const [key, value] of Object.entries(params)) url.searchParams.set(key, String(value));
  const res = await fetch(url);
  if (!res.ok) throw new Error(`${path} returned ${res.status}`);
  return (await res.json()).data;
}

const wallet = process.argv[2]; // a proxy_wallet from the large-trades feed

const [stats, value, positions, firstActions] = await Promise.all([
  get('/v2/user-stats', { user: wallet }),
  get('/v2/value', { user: wallet }),
  get('/v2/positions', { user: wallet, filter_type: 'CASH', filter_amount: 1000, sort_by: 'CURRENT_VALUE', limit: 10 }),
  get('/v2/activity', { user: wallet, sort_direction: 'ASC', start: 1, limit: 1 }),
]);

console.log({
  marketsTraded: stats?.trades ?? null,
  biggestWinUsd: stats?.biggest_win ?? null,
  portfolioUsd: value.value,
  firstSeen: firstActions[0] ? new Date(firstActions[0].timestamp * 1000).toISOString() : null,
});

for (const p of positions) {
  console.log(p.outcome, p.title, Math.round(p.current_value), Math.round(p.unrealized_pnl));
}

A snapshot of open positions shows conviction, not skill. For a track record, request status=CLOSED on /v2/positions, which returns exited positions sorted by realized PnL by default.

How do you follow a whale's activity?

Poll /v2/activity for each wallet on your watchlist:

curl -s "https://data-api.polymarket.com/v2/activity?user=0xWHALE_WALLET&limit=50"

It returns trades plus splits, merges, redemptions and rewards, newest first, each with usdc_size, the cash value of the action. Deposits and withdrawals are left out unless you pass exclude_deposits_withdrawals=false.

Activity is the better feed for wallets you already know. It was cached for 15 seconds in our checks, against five minutes for trades, and it shows maker fills. When we followed one wallet behind a $21,000 buy, its activity showed three more fills in the same market at 94 cents within a second, which the default trades feed left out because they filled as maker. Add taker_only=false to /v2/trades to include those, then de-duplicate, because one fill can then appear for both the taker and the maker.

How do you use the leaderboard to find whales?

Large trades find wallets that moved money today. The leaderboard finds wallets that made money over a period:

curl -s "https://data-api.polymarket.com/v2/leaderboard?time_period=week&sort_by=PNL&limit=50"

Each row carries rank, user_id (the wallet), pnl and volume. Volume counts shares on both sides, never dollars, so a wallet trading one-cent contracts can rank high on the volume board with little money behind it. A strong watchlist keeps wallets that show up in both places: large trades this week and a place on the weekly or monthly PnL board. Every parameter is covered in our Polymarket leaderboard API guide.

What can mislead a Polymarket whale tracker?

• Near-settled trades. In our checks, the three largest trades of the previous eight days were sales at 99.9 cents of outcomes that had all but won, worth $1.7 million to $2.1 million each. A fifth of the 100 trades over $100,000 were priced at 95 cents or more. Those read as exits, not new views, so consider skipping prices near 0 or 1.
• Brand-new wallets. One wallet made five buys worth about $140,000 within 80 minutes of its first trade, and /v2/user-stats still returned data: null for it. Treat null as "no stats yet" and read its first activity instead. Gamma's /public-profile?address= also returns the profile's createdAt.
• Hedges and market making. A large fill can be one leg of a hedge or a market maker's inventory. The mergeable flag on a position shows when a wallet holds both outcomes of a market.
• Size is not skill. Large wallets lose too. One wallet behind a $21,000 trade in our checks also held a position marked about $18,700 below its cost.

Acting on someone else's trade carries the same risk as any trade, plus the cost of arriving late, which our copy trading guide covers in detail.

How do you track whales across prediction markets?

Polymarket's Data API answers for Polymarket, and large traders work other venues too. The Predictefy API scores trades from nine venues, including Polymarket, Hyperliquid, Limitless and Myriad, and tags each one with the wallet's category at the time: bot, whale, smart, fresh or fish. One request returns the whale trades from all of them:

import Predictefy from '@predictefy/sdk';

const client = new Predictefy({ apiKey: process.env.PREDICTEFY_API_KEY });

const whaleTrades = await client.fetchSmartMoney({
  category: 'whale',
  minScore: 60,
  window: 'day',
  limit: 50,
});

for (const trade of whaleTrades) {
  console.log(trade.venue, trade.wallet, trade.side, trade.usdSize, trade.tradeScore, trade.categoryAtTrade);
}

Frequently Asked Questions