Photo by roku Activate on Flickr

Roku Inc (ROKU) shares shot up over 4.5% and ViacomCBS Inc (VIAC) shares were up over 2.6% at the end of the regular session on Wednesday.

What Happened: The movement in the stock prices was fueled by a report from The Wall Street Journal that Comcast Corporation (CMCSA) CEO Brian Roberts is eyeing a possible collaboration with ViacomCBS or acquiring Roku in a bid to buttress the company’s future in streaming.

A Comcast spokesperson dismissed the report as speculation, CNBC reported. 

On Wednesday evening, Roku shares rose 4.5% to $421.70 in the regular session and another 0.5% in the after-hours trading. On the same day, ViacomCBS shares closed 2.67% higher in the regular session at $41.84 and rose another almost 0.6% in after-hours trading.

Comcast shares closed 3.73% lower at $55.48 in the regular session on Wednesday and gained 0.13% in the after-hours trading.

Why It Matters: The Journal noted that Comcast subsidiary NBCUniversal’s Peacock service is lagging rivals such as Netflix Inc (NFLX) and The Walt Disney Co (DIS) in terms of paid subscribers.

In late April, while Peacock had 42 million sign-ups, in May it had fewer than 10 million paid subscribers. Netflix and Disney's numbers amounted to 208 million and 103.6 million globally in the first quarter.

Comcast’s streaming plans also span a partnership with Walmart Inc WMT 0.04% and Chinese firm Hisense Home Appliances Group Co, Ltd HISEF for the development of smart televisions, which could appear in stores later this year, as per the Journal.

Meanwhile, NBCUniversal CEO Jeff Shell said this month that depending on the ratings, the soon-to-be-held Tokyo Summer Olympics could be “the most profitable for the company.”