Yes, VWAP in the last 30 sec of reg trading hrs. In that thread you mentioned:
Did the overnight limit change?
I copied yesterday's limits, pasted here for ease of reading:
So, what
@TickSeeker noticed with NQ, also happened with ES (but I won't post any screenshots).
I don't really understand the entirety of it, but here're the rules for ES:
https://www.cmegroup.com/trading/equity-index/faq-sp-500-price-limits.html
So, because NDX and SPX hit their 7% limit (crazily at about the same time) (at approx noon Chicago time), then the futures were halted too, but, and I never noticed this before, the halt doesn't seem to be shown in the futures charts in some software packages!! The halt is a horizontal line in ndx/spx, but in nq/es the data is just missing in TOS (but it does show as a flat line in IB's TWS).
And after that, the 13% limit is the new limit. Bingo.
Note, I haven't dissected the logic of that page, but at first glance I can't see why they even have the futures limits if they're never triggered unless the underlying is triggered first (which has it's own limit).
I eagerly await clarification by one of the ET futures gods....
Theres another thread on ET that says the price is based on the VWAP not the closing price