Two Polymarket Whales Face Off in $500K Seahawks-Broncos Showdown

Massive Sums Moved for Single Game

At 22:34 UTC on Oct. 13, a single Polymarket transaction paired two of the platform’s biggest sports traders on opposite sides of Thursday Night Football. An account trading as BreakTheBank bought 500,528 Broncos shares at 42 cents, spending $213,879. Its order was filled by six resting limit orders from surfandturf on Polymarket’s public order book, which bought 500,000 Seahawks shares at 58 cents for $290,000.

Polymarket shares are binary contracts that pay $1 if the outcome happens and nothing if it does not, so the trade created a pot of about $500,000 that goes to whichever side wins. If Denver wins, then BreakTheBank, which has since added a few hundred shares and holds 500,812, would clear about $287,000. If Seattle wins, then surfandturf, which has sold about 7,100 shares at around 57 cents and held about 492,900 on Wednesday, would clear about $207,000.

Each account is now by far the largest holder on its side of the moneyline market, where about 537,000 shares have traded in total. The market had Seattle at 57% on Wednesday. The game kicks off at 8:15 p.m. ET on Thursday, Oct. 15, in Denver. Single-game positions this size can swing late: On Oct. 11, another account lost a $147,000 Eagles bet to a 57-yard field goal as time expired.

BreakTheBank, created in January, sits first on Polymarket’s weekly and monthly profit leaderboards, at $2.13 million and $3.57 million, and is up $7.04 million all-time. This week it netted about $913,000 on the Buffalo Bills’ 37-34 overtime win over the Los Angeles Rams on Monday night, and $458,182 on Barcelona’s 4-1 win at Galatasaray in the Champions League on Tuesday.

The account called surfandturf was created in April and is up about $67,000 all-time after losing about $718,000 this week. It lost $413,671 backing the Atlanta Falcons, who fell 30-23 to the Baltimore Ravens on Sunday night, and $61,000 on the Rams in the game BreakTheBank won. The two have been on opposite sides before: On Sept. 27, surfandturf lost $515,803 on the Rams against the Broncos, a game on which BreakTheBank made about $306,000 backing Denver.

In their most recent trades, surfandturf bought only one side of each market, which points to a directional bettor rather than a market maker—the latter being a user who posts orders to both buy and sell in a market and profits from the gap between those prices, whoever wins. A directional bettor picks a side and wins or loses with the result.

Kalshi set back-to-back daily volume records over the weekend, at $3.91 billion on Saturday and $3.96 billion on Sunday. Parlay-style…