Confused with Options Timings and Settlement Price

[Moneyo]

I recently executed a trade on Wall Street DJIA Options with 19th June Expiry on my Demo Account.The trade was initiated on 12th June where 26100 call was sold to open at 178 points.Today was expiry date and US Markets were still trading and something caught me off guard as I saw my position closed at a very strange settlement price.26484 as a settlement price was used .there's no way market made even came that close for even a second.I am confused and scared with what I witnessed.

[Kodiak]

"12. Bets on US 500, US Tech 100 and Wall Street options can be dealt until the close of business on the Thursday before the third Friday. They expire based upon the Special Opening Quotation of the S&P 500 Index on the 3rd Friday of the contract month."

 

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