• Walmart increased its full-year outlook after beating earnings expectations.
• Warner Bros. Discovery and the National Basketball Association settled legal disputes over live game rights.
• Trump Media is reportedly in talks to buy crypto firm Bakkt, sending shares higher.

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

1. Market tension

Stock futures were slightly lower Tuesday as Ukraine-Russia tensions increased and investors anticipated earnings from retailers and Nvidia. Futures tied to the Dow Jones Industrial Fund dropped 0.56%, while S&P 500 futures were down 0.38% and Nasdaq 100 futures fell about 0.27%. Follow live market updates.

2. 'Tis the season

Walmart increased its full-year outlook on Tuesday as it beat Wall Street's third-quarter earnings expectations. The nation's largest retailer now expects full-year net sales growth between 4.8% and 5.1%, up from its previous forecast for growth between 3.75% and 4.75%. Customers visited both stores and the website more than the year-ago quarter, and tended to spend more when they did, as U.S. transactions rose 3.1% and the average ticket increased by 2.1%. In a CNBC interview, Chief Financial Officer John David Rainey said consumers are waiting to make general merchandise purchases until they see a compelling deal and expects the trend to continue into the holiday season.

3. WBD exits the stadium

Warner Bros. Discovery settled all legal disputes with the National Basketball Association over the media company's attempt to own a package of live NBA games in the U.S. for the 2025-26 season and beyond. Warner Bros. Discovery sued the league in July and accused it of failing to allow it to use so-called matching rights on a package of live games. The settlement officially ends Turner Sports' 40-year tenure as a carrier of live NBA games after this season, but will keep the company attached to some NBA content, production partnerships and licensing deals.

4. When Trump talks

Shares of the cryptocurrency trading firm Bakkt jumped 167% after the Financial Times reported Trump Media was in "advanced talks" to buy the company. Trump Media, which is majority owned by President-elect Donald Trump, shot up by double digits minutes after the Financial Times report was published and closed more than 16% higher. The reported talks show Trump is further developing his business interests in the cryptocurrency realm, even as he is set to enter the White House in January.

5. Super Micro hires auditor

Super Micro Computer said on Monday it has hired BDO as its new auditor and submitted a plan to Nasdaq to regain listing compliance with the exchange. Shares jumped 37% in extended trading after the news broke. The server maker is late in filing its 2024 year-end report with the SEC amid trouble holding onto an accountant.

— CNBC's Pia Singh, Melissa Repko, Alex Sherman, Kevin Breuninger and Kif Leswing contributed to this report.