Finding Dory” is swimming toward its third straight victory at the U.S. box office during the four-day holiday weekend with $50 million-plus, topping “The Purge: Election Year,” “The BFG” and “The Legend of Tarzan,” early estimates showed Friday.

The third “Purge” film and “Tarzan” are battling for the second slot with preliminary forecasts for both in a wide range between $30 million and $37 million, while “The BFG” is heading for a disappointing $25 million.

Friday estimates showed that the opening day of Universal-Blumhouse’s “The Purge: Election Year” would earn between $12 million to $14 million — with “Dory” taking in about the same amount on its 15th day of of release.

By the end of business on Monday, “Dory” will finish the weekend with more than $380 million domestically in 18 days, trailing only “Captain America: Civil War” among 2016 titles.

“The Purge” sequel, playing at 2,796 sites, is going to be another money-maker for Universal with a price tag of only $10 million. The original “The Purge” grossed $64 million in the U.S. in 2013 and “The Purge: Anarchy” reeled in $72 million the following year.

The films take place in a future America in which all crime, including murder, is legal for one night a year. “The Purge: Election Year” stars Elizabeth Mitchell as a presidential candidate whose platform includes eliminating The Purge. Frank Grillo returns as anti-Purge bodyguard.

Warner Bros.’ “Tarzan” generated early Friday estimates ranging from $9 million to $12 million at 3,561 sites. The latest version of the Edgar Rice Burroughs story, starring Alexander Skarsgård and Margot Robbie, may match forecasts, which had called for about $35 million over the four days.

The pic, co-produced with Village Roadshow, carries a hefty $180 million budget and will require strong performances overseas in order to make it into the black. Warner Bros. is opening “The Legend of Tarzan” in 19 international markets this weekend, including South Korea and Russia. Reviews have been largely negative with a 34% rating on Rotten Tomatoes.

“The BFG” is also underperforming forecasts, which had projected an opening in the $30 million range. Friday’s debut day looked likely to hit between $6 million and $8 million. The Roald Dahl adaptation has received plenty of affection from critics with a 73% rating on Rotten Tomatoes, thanks to Mark Rylance’s motion-capture work as a giant who befriends an orphan girl.

But “The BFG” will likely struggle to break even, given its high-priced $140 million budget, funded by Amblin Partners, Disney and Walden Media.

Fox’s second weekend of “Independence Day: Resurgence” looks likely to finish in fifth with about $20 million this weekend, following its $41 million launch. The tentpole was the latest in a long line of sequels that have delivered less than stellar results this summer, including “Alice Through the Looking Glass” and “Teenage Mutant Ninja Turtles: Out of the Shadows.”

The recent slump has resulted in the 2016 summer season lagging its 2015 counterpart by more than 5.5% at $1.86 billion as of Monday, according to comScore. The decline has been so pronounced that the year-to-date box office — which had surged during the first quarter — is now in a virtual tie with last year’s halfway total of $5.57 billion.

“As another group of new films step up to the summer box office plate, a crowded marketplace gets even more crowded as moviegoers are offered a ton of choices as the industry anxiously awaits the next breakout hit of which there have been precious few this summer,” said Paul Degarabedian, senior media analyst with comScore.

“This summer lineup needs to kick it into high gear to right the ship and get things on track,” he added. “It all comes down to the product and when a holdover film like ‘Dory’ can hold off newcomers for three straight weeks, that is an indication that audiences are collectively holding back their hard-earned dollars and waiting for the next big thing and we need that next big thing in a hurry.”

Dergarabedian said there are still plenty of potential successes on the horizon, such as Universal’s “The Secret Life of Pets,” which opens July 8, and “Jason Bourne,” and Warner’s “Suicide Squad,” to energize this summer before it ends.

The top Fourth of July weekend came three years ago when “Despicable Me 2” opened with $83.5 million and led the way to a $230 million total for the July 3-5 frame.