Massive change in Options price in the last second

For SPX options expiring June 2021, for 4200 CALL what is the close price which people are seeing with their broker? With TDA I am seeing its $20.
It was trading around $9 for the whole day and at close the mid suddenly jumped to $20.

I think this is some random fluctuation. But just wanted to confirm what others are seeing with other brokers.

 

And the bid/ask chart during the last 30 minutes of trading:

 

Wow. With TDA the bid ask is 0.00 and 40.00. Something wrong with TDA.

 

Also just checked IQFeed, and it does show bid/ask as $0/$40:


So it's possible that bids go away after market closes, while some brokers like IB may be preserving the last bid/ask available before market closes.

 

https://www.zerohedge.com/markets/did-someone-just-get-carried-out-sp-futures

 

Interesting.
Did affect the cash open?

 

What is quadruple witching?
https://www.foxbusiness.com/markets/what-is-quadruple-witching

 

No. The Special Opening Quote was 3161.26

I was short the 3150 straddle so I'm glad the SOQ has nothing to do with the last futures price.

 

This happens all the time. Towards the close the price goes wack one way or another.

This usually means no more trading today.

You can always put in a price and see what happens.

I don't like this because your position is usually marked at an interval between the high and the low. Can make it look like you have lost more than you really have.

Just how the game is played.

 

TD/TOS often has wild gyrations on their closing marks.Ive gotten used to it,but if I was out there trying to raise capital,I woukd not be so cavalier..