Investors bought up the stocks of Time Warner Inc. and 21st Century Fox Inc. on June 13 after a judge ruled to allow the acquisition of one and an unsolicited acquisition offer formally touched off a bidding war for the other.

Shares of Time Warner rose 1.8% to close at $97.95 the day after a judge ruled that its acquisition by AT&T Inc. could move forward. Buyer AT&T saw shares tumble by 6.2%, to close at $32.22.

Meanwhile, Fox shares shot up 7.7% to close at $43.66 as investors awaited a fresh acquisition offer from Comcast Corp., which had earlier announced its intention to challenge an earlier offer from Walt Disney Co. for the media and entertainment assets held by Fox. Under the terms of the offer, announced after-market June 13, Comcast would pay $35 per share in cash, which represents a premium of about 19% to the value of Disney's all-stock offer as of 12 p.m. ET on June 13. Fox in December 2017 had agreed to sell its entertainment assets to Disney for approximately $52.4 billion in stock.

Comcast on June 13, 2018, cited the AT&T/Time Warner ruling in explaining the rationale for the timing on its latest acquisition offer, as well as an upcoming Fox shareholder meeting, which is scheduled to occur July 10.

In the June 12 ruling, U.S. District Court Judge Richard Leon rejected the U.S. Department of Justice's argument that the AT&T-Time Warner combination would give the resulting entity too much power in the pay TV and online video marketplace, approving the deal without conditions. AT&T plans to close the transaction on or before June 20.

Comcast's shares fell 0.19% June 13, closing at $32.32. Disney's shares added 2% to close at $106.31.