Media stocks took a dive this week, following bad news about subscriber numbers for pay TV (~400,000 below expectations) and worrying comments from Turner about the TV ad market.

The subscriber decline, in particular, should concern cable and satellite TV companies. "After two quarters of slight improvements, pay TV subscriber declines appear to have accelerated markedly in 1Q17," UBS analysts led by Doug Mitchelson wrote in a note Wednesday. One thing this could mean: The new streaming TV bundles (vMVPDs), such as YouTube TV and DirecTV Now, aren't the savior the industry was hoping for — at least not yet.

"The cord cutting acceleration contrasts with the media bull case that [streaming TV packages] will stabilize or improve pay TV declines," UBS wrote.

UBS gave a few potential reasons for the acceleration of subscriber losses:

Price increases on traditional services could be causing more people to cancel.

"Promotional intensity" could have gone down, especially on lower-end tiers.

Perhaps some of the early sign-ups to new streaming TV bundles were doubling up, and keeping their traditional TV packages. Those people could now be canceling.

Whatever the reason, the decline is likely to spark fears that cord-cutting will finally start to get moving in a way that will hurt the pay TV industry. For instance, in a recent report on the future of ESPN, Morgan Stanley wrote that the growth of streaming TV services would cause “subscriber erosion trends to improve.” Basically, that these services would turn around the growth picture. That might not be the case.

“The industry can’t resist change anymore,” industry analyst Michael Nathanson wrote in a note about cord-cutting, according to Variety. “The future has arrived.”

Here is a chart from UBS that puts that into perspective, showing how subscriber declines have accelerated (both with and without new streaming bundles):