At market close (August 27th), I will check BoxOfficeMojo. This market resolves YES if the "WORLDWIDE" gross displayed is >$1 billion.
Details
Box office reporting has a delay, so I added +1 day to the close date to better capture the spirit of "within a month". [1]
All that matters for the purpose of resolution is what BoxOfficeMojo displays at market close.
Example: "Deadpool 2" currently lists a "WORLDWIDE" gross of $785,896,632.
For informal context, "Black Panther" crossed $1 billion in 26 days, while "Jurassic World" only needed 13 days (according to news outlets—this market only resolves based on BoxOfficeMojo).
[1]. I don't expect this to have any impact—the key delay is international gross (which roughly updates ~weekly), but the 26th is a Monday and BOM basically always updates its international estimates by EOD Monday (I pushed it to Tuesday just to be safe).
"DEADPOOL & WOLVERINE" DASHBOARD
@traders Cruised past $1B after its 2nd weekend. Resolves YES. Bet on the WW gross for "Alien: Romulus" next:
https://deadline.com/2024/07/deadpool-wolverine-global-international-box-office-1236023236/
Based on this estimate it seems likely now. (A better global opening than Black Panther for reference).