A curious thing happened to the cable television industry after HBO and CBS announced streaming services that deeply threaten the lucrative cable bundle: The cable companies’ stocks have been climbing higher.

Shares of Comcast and Cablevision are each up 6 percent since HBO made its big announcement last Wednesday. Time Warner Cable is up nearly 3 percent, and Charter has risen almost 9 percent.

The great unbundling of the cable television package is closer, but it’s far from the end of cable companies. On Thursday, Comcast released its third-quarter results, showing a 10 percent increase in operating income.

The same companies that for decades have offered all-or-nothing TV plans with hundreds of channels will still sit at the center of the new online video economy for one simple reason: They control the Internet pipes.

And for consumers, it’s not clear if they will actually end up with better and more affordable options if only a few companies control broadband access.

“If there isn’t a lot of competition, which there isn’t, then there is a lot less reason to keep prices down” said Matt Wood, a policy director at public interest group Free Press. He notes that if Comcast’s $45 billion acquisition of Time Warner Cable is approved, the combined firm would control more than 40 percent of the market for the highest Internet speeds.

“Could they price broadband higher? That’s where competition policy is so important, to ensure their consumers have more choices and that prices stay down,” Wood said.

The companies say they won’t reduce competition because they hardly overlap in local markets. Comcast also disputes that it will control the broadband market, saying it will have only 35 percent of all high-speed connections.

Comcast’s two major businesses — from cable television and broadband — already are becoming equals.

Comcast has 21.6 million Internet subscribers and 22.4 million cable TV subscribers. Most of those customers still get both services.

But the trends are clear: Last year, a total of 166,000 cable subscribers across cable providers cut the cord, according to SNL Financial. In the third quarter, Comcast lost 81,000 cable television subscribers but saw an increase of 315,000 broadband Internet subscribers.

And analysts say that means Comcast has no choice in the long run but to raise prices for broadband or create new streams of revenue through partnerships in online video.

If cable subscriptions continue to decline, “the one lever I have to pull is broadband pricing,” telecom research analyst Craig Moffett of MoffettNathanson said about cable firms during a client conference call this week. He warned investment clients that regulators will pay close attention to any aggressive increases in Internet prices.

“Everyone who owns these stocks does so because they think the stocks have broadband pricing power,” Moffett said.

This point has indeed caught the attention of regulators, who are still reviewing the proposed deal between Comcast and Time Warner Cable, as well as deals between companies such as Netflix and Comcast that are designed to guarantee faster streaming to Netflix subscribers. Earlier this week, the FCC said it would pause its review of Comcast’s bid for Time Warner Cable and AT&T’s proposed acquisition of DirecTV to give itself time to figure out how to handle confidential documents related to the deals.

Steve Burke, Comcast executive vice president and NBC Universal chief executive, was asked in an earnings call Thursday how the streaming-video plans from HBO and CBS will affect Comcast. Burke said he was surprised by their announcements but played down the threat, saying the television networks will continue to rely heavily on cable television distributors.

“Both HBO and CBS are trying to add to their existing ecosystem. I don’t think they are trying to say they are going over the top of their existing ecosystem,” Burke said. The challenge for HBO “is to attract new customers into the ecosystem without cannibalizing their existing business.”

HBO and CBS are looking to attract younger audiences who don’t already have cable television. And the firms were careful last week in comments about their cable partners, saying that most of their revenue will still be tied to distribution deals with cable television providers.

“I have spoken to almost every CEO of every major distributor. I don’t think anyone is upset. It’s their broadband and their ISP,” HBO President Richard Plepler said in the streaming announcement. “I don’t believe any of these things are mutually exclusive.”

Ultimately, the power of Comcast and other cable companies could mean that the promised land of a la carte video will not be a clear victory for consumers.

“The fact that HBO and CBS made their announcement doesn’t change the fundamental power arrangement,” said Gene Kimmelman, the president of public interest group Public Knowledge and a former Justice Department antitrust official.