Market-on-open buy order on NYSE not filled

When a buy market-on-open order on NYSE is not filled, which criteria determine which market-on-open orders get filled?

 

As long as there is a seller. I've never encountered anything like that. Did you make sure the order was active on the exchange beforehand? I've seen order being held by the broker, obviously not executing.

 

It is my understanding that a MOO order sent before the 9:28 am cut off should get filled.

 

I sent the order well before the 9:28 cut off. It was a liquid stock, however for some reason the auction/cross volume was not large. My order was larger than the auction/cross volume. I did not get a partial fill. I have not experienced it before.

I believe I read somewhere that the NYSE opening process has changed due to Covid-19.

 

That was also my understanding until today. Maybe it is because of changes in the opening auction/cross process on NYSE due to Covid-19?

 

You are correct. I just called the NYSE trade desk and ask for a copy of the updated rule.

 

From NYSE- https://www.nyse.com/publicdocs/nyse/NYSE_Floor_Closure_FAQ_20200320.pdf
https://nyseguide.srorules.com/rule...CC-BAC2-43EB20902159}--WKUS_TAL_19401#teid-41

 

Looks like a complete mess and completely unnecessary when NASDAQ can open everything electronically with relative simplicity.

 

Anecdotally, I have traded hundreds of thousands of MOO orders, seen, maybe.. a few dozen that did not fill, but I have never once seen a partial fill. The implication is that you might be able to achieve a partial by breaking up your own order into multiple smaller MOOs, since it seems the matching engine won't split them for you.