• Comcast will spinoff its cable network channels, people familiar with the matter told CNBC.
• The U.S. closed its embassy in Kyiv on Wednesday amid rising tensions with Russia.
• SpaceX launched the sixth test flight of its Starship rocket on Tuesday, its fourth in 2024.

Here are five key things investors need to know to start the trading day:

1. Investors await

Stock futures inched higher Wednesday as Wall Street anticipates Nvidia's earnings report after the bell. Futures tied to the Dow Jones Industrial Average rose about 0.16%, while S&P 500 futures increased 0.09% and Nasdaq 100 futures ticked up by 0.07%. Follow live market updates.

2. Comcast to split

Comcast plans to move forward with the spinoff of its cable network channels, people familiar with the matter told CNBC on Tuesday. The networks that are part of the spinoff include CNBC, MSNBC, E!, Syfy, Golf Channel, USA and Oxygen, a person close to the matter said. The separation is expected to take about a year, and will give the cable networks the optionality to merge with other networks or potentially be sold to private equity, one of the people said. A formal announcement from the company could come as early as Wednesday.

Disclosure: Comcast owns NBCUniversal, the parent company of CNBC.

3. Missed the bullseye

Target on Wednesday missed Wall Street's third-quarter earnings expectations and posted only a slight uptick in customer traffic. The retailer cut its full-year guidance to adjusted earnings per share between $8.30 and $8.90, down from the $9 to $9.70 per share that it expected in August. Target missed Wall Street's earnings per share estimate by 20%, its biggest in two years, and saw its first revenue miss since Aug. 2023.

4. Nuclear tensions soar

The U.S. closed its embassy in Kyiv on Wednesday warning that it "received specific information of a potential significant air attack" amid rising tensions with Russia. The U.S. Embassy said in a statement that it was closing the building "out of an abundance of caution" and instructed embassy employees to shelter in place. Ukrainian news outlets and the Russian government confirmed Ukraine launched six U.S.-made long-range missiles against the Bryansk border region on Tuesday. Russian President Vladimir Putin signed a decree the same day that shifted the parameters on when Russia can use nuclear weapons, raising concerns among global markets.

5. A space spectacle

SpaceX launched the sixth test flight of its Starship rocket on Tuesday, its fourth in 2024. The un-crewed Starship took off from the company's facility near Brownsville, Texas, before splashing down intentionally about an hour later in the Indian Ocean. Starship is both the tallest and most powerful rocket ever launched, standing 397 feet tall and about 30 feet in diameter when stacked on the "Super Heavy" booster. President-elect Donald Trump attended the launch, underscoring his increasingly close relationship with the company's CEO Elon Musk, who was chosen to co-lead a government efficiency group for the administration.

— CNBC's Brian Evans, Lillian Rizzo, Alex Sherman, Melissa Repko, Holly Ellyatt, Michael Sheetz and Lora Kolodny contributed to this report.