Boxoffice is online with the first "long range" tracking estimate/projection for April's Avengers: Endgame and they've started the bidding with a domestic three-day opening weekend estimate that would be an all-time record, but stop short of projecting an even Marvel Studios-record final total.
Citing a $250-$290m tracking tracking range, $265m is their initial projection for Endgame's April 26-28 opening dometic frame, which would best its 2018 predecessor Avengers: Infinity War's $257m, the all-time box office opening weekend record unadjusted for inflation.
The box office analysts are also projecting a $695 domestic total, which would also best Infinity War's $679m but fall a few million short of Black Panther's $700m, also last year.
Among the reasons boxoffice cites for its record-setting estimate:
"In a soon-to-be-published interview with boxoffice, Joe Russo — one of the film’s two directors — stated that test audiences have given Endgame 'some of the most incredible responses in Marvel history.'"
Boxoffice has held steady with its $160m opening weekend estimate for Captain Marvel.