Judge John Bates of the U.S. District Court for the District of Columbia ruled against Aetna's proposed Humana deal on Jan. 23, 2017, causing the companies' shares to fall, according to CNBC.
Here are four things to note:
1. Following the news, Aetna and Humana shares both fell by more than 2 percent.
2. In a 156-page opinion, Judge Bates ruled the deal would significantly reduce competition in the Medicare Advantage market in 364 complaint counties and three complaint counties in Florida.
3. An Aetna spokesperson told Bloomberg, "We're reviewing the opinion now and giving serious consideration to an appeal after putting forward a compelling case." A Humana spokesman did not immediately respond to Bloomberg for a comment on the matter.
4. As per the deal's terms, Aetna is set to pay Humana a $1 billion breakup fee.