Since Sept. 1, more than 102,000 Polymarket users have bet on whether Donald Trump or Kamala Harris will be the next president of the United States, propelling Trump’s likelihood of victory to a high of 66.4% despite polls remaining close. According to trading activity, a small number of users are having an outsized impact on the odds.

Nearly half of all purchase volume comes from 670 power traders representing 0.7% of all accounts, according to blockchain data from Dune.com. Many of these users are acting as market makers, buying and selling constantly to earn the small rewards Polymarket pays to accounts that provide liquidity. These users typically play both sides of the market and have limited exposure.

When you remove market makers, you’re left with true “bettors”: users making an actual prediction on the election. In the past seven weeks, bettors have placed $344 million in predictions on the candidates, driving the odds toward Trump. It’s unclear how many of those positions have subsequently been closed out.

Among this subset of users, 16% of bets can be traced to just 10 whales. On Oct. 17, six of these whales drove 37% of predictions. In one 12-hour window, they placed $5.2 million in bets as Trump’s odds rose about four percentage points.

A group of four big accounts tied to a single French national – Fredi9999, PrincessCaro, Theo4 and Michie – have been especially active since Oct. 7, coinciding with a pro-Polymarket post from Elon Musk. If Trump wins, the accounts are in line for a $46 million payout, according to their positions as of Wednesday.