Comcast‘s jump-start to the week – a plan revealed Monday to split into two smaller companies – signals the end of “all under one roof” consolidation in media.

Things have been trending this way for a while, with AT&T’s ill-starred $85 billion acquisition of Time Warner helping to cement the idea that it was possible to be too diversified. Long gone are the days of Redstone or Murdoch empire-building, or GE’s Six Sigma spell-casting. (Fox Corp.’s $22 billion proposal to buy Roku is perhaps a counter-example, but also an outlier at a lower tier of the value chain.)

Post-split, one Comcast entity will be a pure-play entertainment content company, with NBCUniversal and Sky assets, while the other company will be a leading broadband, cable and wireless provider. Despite senior executives’ protests to the contrary, many M&A scenarios will likely be motivated by the new setup.

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Wall Street, which loves deals, also loves the split. Shares in Comcast, which have slid 54% over the past five years, rose 4.5% Monday on more than four times their normal trading volume. A few minutes into Tuesday’s session, they had added another 2%.

There is reason to believe the good times could continue as the split unfolds over the next year. As with Warner Bros. Discovery, which saw its stock surge after it announced plans to split – allowing it to command a huge multiple when it ultimately sold to Paramount in a pending $110 billion deal – Comcast shares have plenty of upside.

RELATED: NBCUniversal & Sky “Fit Well Together And Are Set Up For Success” After Comcast Split, Mike Cavanagh Says

The dynamic that existed for most of the 15-year run of Comcast, whose once-reliably growing broadband business helped offset the volatility of entertainment, has been upended. Cable and broadband operators are under pressure from fiber, while IP and live sports have never been more valuable.

“Ironically, what was once viewed as a way to unlock the value of Cable is now increasingly about unlocking the value of Media,” Bernstein Research’s Laurent Yoon wrote in a research note. “MediaCo,” as he refers to it, “consists of a collection of attractive assets – studios and IP, premium sports rights, and parks – with durable growth profiles and greater strategic appeal. As a result, it should command a higher valuation multiple than the cable business. Beyond the stand-alone value, MediaCo is likely viewed as attractive by strategic buyers, providing an additional source of potential upside.”

Lightshed Partners’ Rich Greenfield maintains that NBCU is “a buyer, not a seller,” as the title of his blog post late Monday put it. “Comcast wants to increase NBCU’s scale, not sell/exit the business,” he wrote. “Bottom line: Being inside Comcast has not only hurt the valuation of NBCU, it has limited its strategic flexibility to scale.”

Brian Wieser, a former Wall Street analyst and advertising exec who runs the Madison & Wall consultancy, says advertising is one of the few areas where synergies actually can be realized at large entertainment companies. “Even seemingly obvious synergies were never fully realized at Comcast (despite being combined for more than 15 years, local TV station sales at NBC’s O&Os are still separate from Comcast’s local cable sales despite often serving the same customers),” he wrote in his newsletter. “This is arguably why few countries have significant distributors and media packagers with common ownership. Canada is one exception, where BCE, Rogers and Quebecor have similarly integrated models.”

The 2009 acquisition of NBC by Comcast, which was rolled up to full control two years later, was a great deal in the view of Chris Marangi, president and co-CIO of Value at Gabelli Funds. “They paid a very attractive price to GE,” he said. “But the world has changed, so it’s not a huge surprise to see the company separating its broadband assets from its content assets.”

Opinions differ about how soon dealmaking could commence. Peter Supino of Wolfe Research predicts a WBD-like bidding war for NBCU, with Netflix among those apt to circle. One caveat in the split is that any transaction during the first year after it takes effect would not benefit from its tax-free structure.

Marangi sees the split as “value-enhancing” for Comcast, regardless of the outcome, given its inexpensive trading level. “I don’t expect anything to happen immediately on the content side, but over time we do expect to see further consolidation among broadband companies,” he said.

Don’t sleep on the cable side. Charter is already in the midst of closing a $34.5 billion blockbuster to absorb rival Cox, and speculation continues about it joining forces with Comcast to give Big Tech a run for its money.