At the time of market creation, the largest sports contract in history was Juan Soto's contract with the New York Mets for $765,000,000. Before this the record was held by Shohei Ohtani's contract with the Los Angeles Dodgers for $700,000,000.

If a new contract is signed before 2026 that beats that $765,000,000 number associated with the Juan Soto contract, this market will resolve YES.

Resolution will be based on the wikipedia page of largest sports contracts:

https://en.wikipedia.org/wiki/List_of_largest_sports_contracts

A description (from the page at the time of market creation) of how figures are counted for the page will give you a sense of what kinds of contracts count for the purposes of this market:

"These figures include signing bonuses but exclude options, buyouts, and the endorsement deals. This list does not reflect the highest annual salaries or career earnings, only the top 100 largest contracts and thus is largely limited to athletes in team sports and auto racing. Athletes in individual sports, such as golf, tennis, table tennis, boxing, kickboxing, and MMA, are not employed by a team and usually earn money primarily through event winnings. This list also does not necessarily reflect actual money collected by the athletes, since some contracts are eventually terminated (usually due to an athlete either retiring or invoking an opt-out clause)."

If there's a controversial contract that could plausibly be reverted from the wikipedia page for whatever reason then I might wait for a few weeks to make sure it remains on this wikipedia page before resolving.