Hollywood's summer at the box office isn't just missing nearly 20 percent of last summer's revenue. It's lacking swagger.

Summer is the season for mega-budget, chest-thumping, globe-trotting monstrosities - films so big they lure droves of Americans with heavily promoted promises of shock and awe. But this season's blockbuster output has been curiously low on the summer's stock in trade: bigness.

Two months into the summer, there haven't been any $300 million grossers at the North American box office. The only movie to surpass $100 million in its weekend debut was "Transformers: Age of Extinction," and it did so by such a small smidge that some box-office watchers claimed it was artificially inflated. The Fourth of July, the customary launching pad for some of Hollywood's flashiest fireworks, was the worst July 4th weekend in at least a decade.

"The first half of the year was extremely strong, as was last year," says Dan Fellman, domestic distribution head for Warner Bros. "Then all of a sudden, it turned the other way."

Since kicking off in early May, the summer box office has totaled $2.25 billion, a 19.3 percent downturn from last summer. Propelled by hit sequels like "Iron Man 3" and "Despicable Me 2," last year was a record summer at the box office, despite a series of high-profile bombs such as "The Lone Ranger," "White House Down" and "After Earth."

But when you bet big, you can win big. While Hollywood's summer has featured no shortage of major blockbusters, it has in some ways been more content to hit a double than swing for the fences. This summer's box office has been dragged down not so much by flops than by a slate of more modestly ambitious movies.

The only major new July 4 release was the Melissa McCarthy comedy "Tammy," made for just $20 million. (It debuted with a lackluster $21.6 million.) One of the season's biggest sensations, "The Fault in Our Stars," was a niche-based hit that appealed to the ardent fans of John Green's young adult book. A whopping 82 percent of its $48 million opening weekend was female. The ensemble comedy sequel "Think Like a Man Too" topped a weekend in June with $29.2 million despite little crossover appeal.

Likely all these movies will be quite profitable for their respective studios due to their cost-conscious budgets. But they aren't superhero-sized hits.

Many of the blockbusters have seen revenue quickly tumble after the first weekend or two. Paramount's "Transformers" - the biggest movie of the summer - nosedived 63 percent in its second weekend. "X-Men: Days of Future Past" opened big with $90.8 million but slid 64 percent the following week. "Godzilla" bowed with $93.2 million only to drop 67 percent.

Large declines aren't uncommon in the blockbuster business, where so much of the marketing push is for opening weekend. But such steep fall-offs contribute to anxiety over the ability of movies to capture and hold the attention of moviegoers in an age of so many other entertainment options. (Cable television and digital media are the villains to this mindset, although the World Cup is another culprit this summer.)

DreamWorks' "How to Train Your Dragon 2" was set up to be the big animated option of the summer following the popularity of the original. But it has seen a muted reception, thus far totaling $141.7 million domestically, well below the $368 million domestic haul of "Despicable Me 2." DreamWorks' Jeffrey Katzenberg has been cynical about the movie industry of late, calling it "not a growth business."

Instead, the studios have been banking on their biggest growth coming from overseas markets. "Transformers" emphasized China more than North America and launched its global assault from there; it has become China's all-time top box-office film, with $223 million in two weeks.

Overseas, star power and spectacle often go further than in North America. Angelina Jolie and Disney's "Maleficent" has brought in $416 million internationally, while Tom Cruise and "Edge of Tomorrow" has nearly tripled its domestic total abroad.

"We're in a global business today and if we lose a little ground in the domestic marketplace, we can pick it up internationally," says Fellman.

But overseas business is little use for North American theaters. Fellman notes it's the exhibitors "that are really suffering this summer."

Yet because of a strong spring led by "Captain America: The Winter Soldier" and "The Lego Movie," the total 2014 box office is down only 3.9 percent from last year.

"We have 'Dawn of the Planet of the Apes' on the way and 'Guardians of the Galaxy,'" says Paul Dergarabedian, of box-office tracker Rentrak. "Luckily there are what I think will be solid performers on the way."

But most of the optimism now has shifted to 2015, when Marvel's "Avengers: Age of Ultron" may become the highest grossing movie of all time. There's a general sentiment that the summer of 2014 is simply an in-between summer.

"Ultimately," says Dergarabedian, "it does come down to the product."