As Fortune noted earlier this week, a handful of blockbuster performances (Wonder Woman, Spider-Man: Homecoming, Dunkirk) have not been enough to overcome a string of pricey box-office flops (King Arthur: Legend of the Sword, Valerian and the City of a Thousand Planets), with the result being a domestic movie ticket revenue total (around $3.8 billion for the summer) that will represent a nearly 16% drop-off from last year’s summer season.

When it’s all said and done, after this Labor Day weekend, the North American box office will have failed to top $4 billion in a summer for the first time since 2006, according to Box Office Mojo.

Hollywood’s dreary summer—plus the fact that 2017 box office revenue is down by nearly 6% for the year-to-date—has left a dark cloud over the movie industry that has not gone unnoticed by Wall Street. The country’s three largest movie theater chains have each seen their stock prices fall over the course of the industry’s lackluster summer. AMC Entertainment, which is majority-owned by China’s Dalian Wanda, has seen its share price plummet by nearly 56% since the start of May (the month that Box Office Mojo counts as the start of Hollywood’s summer season). Regal Entertainment’s stock is down 33% over the same period, while Texas-based Cinemark’s stock is off by almost 23%.

It’s a similar story for IMAX, which operates more than 1,200 large-format movie screens at theaters around the world, as the company’s stock is down nearly 40% since the beginning of May.

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Meanwhile, the actual movie studios that have churned out so many disappointing films this year are also suffering on the stock market, though dismal box office results aren’t the only reason for their stock woes. Walt Disney’s stock is down 12.1% since the start of May.

The Mouse House has not yet lived up to its record-setting 2016 box-office track record, but this year has been far from a flop, especially with at least two more major releases on tap (Thor: Ragnarok and Star Wars: The Last Jedi) before the end of December. But Disney’s investors have experienced turbulence over the past year not just due to movie results, but because of uncertainty around the media giant’s TV properties, particularly as one-time cash cow ESPN continues to lose subscribers. (Paramount-parent Viacom’s stock is down almost 33% during that period, while Time Warner’s is up 1.6% despite both of their major studios seeing declines at the box office this year.)

In other words, most of Hollywood’s major studios are just pieces of larger media conglomerates whose stock prices are affected by a number of shifting industry headwinds, including cable’s loosened grip on TV subscriptions and the rise of streaming entertainment giants like Netflix and Amazon.

When it comes to movie studios and theater chains, though, Wall Street’s concerns stem from the fear that this summer’s disappointments are part of a larger trend that is finding fewer people buying tickets to see movies in a theater. The number of physical movie ticket sales has been slipping for a few years now, with the industry making up lost ground by raising ticket prices.

For their part, studios have kicked around the idea of creating a premium streaming movie service that would see new films made available for downloading at home only a few weeks after they hit theaters. Movie theater operators have not yet fully warmed to that idea, which would look to ride the wave of streaming entertainment’s popularity while offsetting declining DVD sales.

But if those falling stock prices and underwhelming box-office totals are any indicator, those companies may need to be more willing to think outside the box.