Stock in Viacom and CBS rose this afternoon following reports that vice chair Shari Redstone is interested in re-uniting the two media companies that split more than a decade ago.

Viacom’s stock closed at $39.10 today, up nearly 10% over the previous day’s closing price and continuing to rise in after-hours trading, while CBS’s stock closed up 2% at $58.83.

The Wrap reported that Redstone has concluded that, amid a rapidly changing media landscape, the two media companies need to merge to survive. Three unnamed sources told The Wrap that Redstone is actively moving in that direction — though others familiar with the matter told Deadline there are no active discussions taking place.

This isn’t the first time Redstone has considered uniting the broadcast assets of CBS with Viacom’s film and cable holdings. The two companies underwent a rigorous review before calling things off in 2016.

Times have changed since then, with AT&T announcing its bid for Time Warner in late 2016 and, more recently, Disney reaching  a deal last month to buy many of 21st Century Fox’s film and TV assets. The media companies cite the competitive threat of tech giants as animating these deals.

The stock movement is a significant pop for Viacom shares, which have been in a stable range but down a lot from a few years ago after the company has re-oriented itself after downturns at key cable networks. At this time in 2015, shares were trading in the mid-$60s. They began 2014 at $82.