O/U 4.5 Rounds

Each market will resolve to “Over” if the fight between Arnold Allen and Melquizael Costa at UFC Fight Night: Allen vs. Costa, scheduled for May 16, 2026, lasts beyond the listed round threshold. Each market will resolve to “Under” if the fight between Arnold Allen and Melquizael Costa at UFC Fight Night: Allen vs. Costa, scheduled for May 16, 2026, does not last beyond the listed round threshold. For example: “Over 4.5 Rounds” will resolve “Yes” if the fight continues past the 2:30 mark of Round 5. “Under 4.5 Rounds” will resolve “Yes” if the fight ends before the 2:30 mark of Round 5. If the fight ends exactly at the threshold (e.g., 2:30 of Round 5 for a 4.5 line), it will resolve “50-50.” If the bout is not scored, postponed beyond May 30, 2026, or canceled, all options will resolve “50-50.” The resolution source for this market will be official information from the UFC.