• Stock futures are lower as investors await key inflation data and testimony from Federal Reserve Chair Jerome Powell.
• A group of investors led by Elon Musk made a $97.4 billion bid for control of OpenAI.
• President Donald Trump signed an order that would levy a 25% tariff on steel and aluminum imports.

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

1. Tech support

Stocks rose on Monday, boosted by gains among major tech names. The S&P 500 rose 0.67% and the Nasdaq Composite gained 0.98%, while the the Dow Jones Industrial Average added 167.01 points, or 0.38%. Shares of chipmakers Nvidia, Broadcom and Micron all climbed higher during the trading session, along with megacap tech stocks Apple, Amazon and Microsoft. But stock futures were lower before the bell Tuesday, as investors await key inflation data and digest President Donald Trump's latest tariff threats. Follow live market updates.

2. OpenAI offer

A group of investors led by Elon Musk made a $97.4 billion offer for control of OpenAI on Monday, CNBC confirmed. But the eleven-figure bid for the nonprofit behind the AI startup was rejected by OpenAI CEO Sam Altman, who replied in an X post, "no thank you but we will buy twitter for $9.74 billion if you want." Altman told CNBC Tuesday morning that he believes Musk's unsolicited offer is an attempt to "slow down a competitor" and responded "not particularly" when asked how seriously he is taking the bid. Musk's offer comes amid a bitter battle between the two tech leaders. After co-founding OpenAI with Altman as a nonprofit in 2015, Musk has since sued the company and its CEO in an attempt to keep OpenAI from converting to a for-profit corporation.

3. Steel yourself

President Donald Trump introduced his latest round of tariffs Monday evening, signing an order that would levy a 25% tariff on steel and aluminum imports. Trump initially announced his plan to impose the new duties over the weekend, causing stocks tied to the two metals to climb during the trading day Monday. Shares of steel manufacturer Cleveland-Cliffs surged nearly 18%, while Nucor and U.S. Steel both rose around 5%. Aluminum company Alcoa meanwhile closed 2% higher. The new tariffs, which are set to take effect on March 4, come one week after Trump paused planned tariffs on Canada and Mexico.

4. Earnings pop

Shares of Coca-Cola climbed nearly 4% Tuesday morning after the beverage giant topped Wall Street's earnings and revenue expectations for the fourth quarter. The company said that rising global demand for its drinks led to its net sales growing by 6% for the quarter, reporting $11.54 billion in revenue and 55 cents in adjusted earnings per share.

5. On the Hill

Federal Reserve Chair Jerome Powell will testify before Congress Tuesday morning, beginning two days of semiannual hearings on monetary policy on Capitol Hill. Powell will first address the Senate Committee on Banking, Housing, and Urban Affairs at 10 a.m. ET on Tuesday, followed by the House Committee on Financial Services at 10 a.m. on Wednesday. The hearing comes as President Trump continues to send mixed messages about his approach to the Fed. After ripping the central bank in a Truth Social post following its decision to keep rates steady in January, Trump later approved of the Fed's move.

— CNBC's Pia Singh, Brian Evans, Hakyung Kim, Ari Levy, Lora Kolodny, Arjun Kharpal, Ryan Browne, Chloe Taylor, Ganesh Rao, Spencer Kimball and Amelia Lucas contributed to this report.