In 2008 we saw the birth of what has come to be known as the Marvel Cinematic Universe with the release of Iron Man. Eleven years, 21 films and $18.6 billion in worldwide ticket sales later, that universe has come to redefine the idea of the modern blockbuster. This weekend Avengers: Endgame will give audiences the ending they were promised all those years ago, concluding the events that began with last year's record-breaking release of Avengers: Infinity War, en route to a sure-fire record breaking performance of its own.

Before a single frame outside of the trailers had been seen, Disney and Marvel Studios's Avengers: Endgame began breaking records. In its first seven days of pre-sales, the film sold "five times" as many tickets as Avengers: Infinity War according to online ticket retailer Fandango.com and since then it remains the company's top pre-seller of all-time. Further more, the film will open in a record number of theaters, debuting in over 4,600 locations this weekend with thousands of showings already sold out, and several locations set to remain open 24 hours a day throughout the weekend. To that end, on Tuesday, one theater began playing each film in the Marvel Cinematic Universe back-to-back-to-back leading up to the debut of the new film, complete with shower and food breaks.

Overall, Fandango.com tells Mojo, on top of Endgame pacing to be the online ticket retailer's biggest pre-seller of all-time, it broke Fandango's best first-day sales record (previously set by Star Wars: The Force Awakens) in just six hours. Additionally, Endgame has sold out over 4,000 showtimes and interest in the upcoming release has resulted in the site's FandangoNOW service seeing a nearly 50% increase in transactions on Marvel titles in the weeks since Endgame tickets went on-sale.

That being said, forecasting the film's opening beyond anticipating a record performance is difficult to accurately predict. Given the hype, overall reach of the film and the mostly positive reviews (78 on Metacritic and Certified Fresh at 97% on RottenTomatoes) a debut reaching $300 million isn't at all unrealistic. In fact, such a result would be fitting considering it was The Avengers in 2012 that became the first film to ever gross over $200 million in its opening weekend. The better question, perhaps, is to wonder just how many records will Endgame break?

Records the film will almost certainly challenge related to this weekend alone include:

• Largest Thursday Preview Gross
• Current Record: Star Wars: The Force Awakens - $57 million
• Largest Friday, Opening Day and Single Day
• Current Record: Star Wars: The Force Awakens - $119,119,282
• Opening Weekend, April Opening, Spring Opening, PG-13 Opening and 3-Day Gross
• Current Record: Avengers: Infinity War - $257,698,183
• #1 Movie Market Share
• Current Record: Avengers: Age of Ultron - 84.5%
• Saturday Gross
• Current Record: Avengers: Infinity War - $82,131,612
• Sunday Gross
• Current Record: Avengers: Infinity War - $69,231,632
• Fastest to $150M, $200M and $250M
• Current Record: Avengers: Infinity War
• Fastest to $300M
• Current Record: Star Wars: The Force Awakens
• Top Opening Theater Average and Top Theater Average
• Current Record: Star Wars: The Force Awakens - $59,982

Beyond those records, this will help contribute to what should be the largest weekend ever, a record the film may have a shot at breaking all on its own. The current record belongs to the weekend of December 18-20, 2015 when Star Wars: The Force Awakens debuted with $247.9 million. The runner-up is also the April record, which currently belongs to the weekend when Infinity War opened last year.

The film's domestic opening, however, isn't all we'll be tracking. Endgame debuts day and date in virtually all major territories beginning today with its release in China, France, Germany, Italy, Australia, Korea and many others. In fact, the film's opening in China is already estimated to have topped $107 million, which includes $28.2 million from Tuesday's midnight showings. The performance is the highest opening day of all-time in China.

Looking ahead, Endgame will open in the UK and Brazil tomorrow followed by a launch in Spain, Japan and Mexico on Friday along with virtually every other market outside of Russia where the film opens on Monday, April 29. To say expectations are for the film to break not only the domestic opening record but the international and worldwide opening records is something of a foregone conclusion.

Currently, Infinity War holds the worldwide opening record with $640.5 million, doing so without the advantage of China, where the film opened a couple weeks later with $191 million. Meanwhile Fate of the Furious holds the international opening record at $443.1 million. Look for those two records to fall this weekend as some analysts have Endgame targeting as much as $900+ million worldwide.

This weekend's forecast is directly below. This post will be updated throughout the week as new details are released, including Friday morning with Thursday night preview results followed by Friday estimates on Saturday morning, and a complete weekend recap on Sunday morning.

1. Avengers: Endgame - $300.0 M
2. The Curse of La Llorona - $10.5 M
3. Shazam! - $9.1 M
4. Captain Marvel - $7.3 M
5. Breakthrough - $6.1 M
6. Dumbo - $3.8 M
7. Little - $3.8 M
8. Missing Link - $2.4 M
9. Pet Sematary - $2.3 M
10. Us - $1.9 M