• Stock markets tumbled Tuesday on tariff concerns.
• Industries warned the levies would hit their businesses.
• President Donald Trump addressed a joint session of Congress.

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

1. Losses keep coming

The Dow Jones Industrial Average fell again Tuesday, shedding 670.25 points, or 1.55%, and bringing its two-day losses to more than 1,300 points as investors fear the effects President Donald Trump's new tariffs could have on the economy. The S&P 500 dropped 1.22%, pushing the index into the red for 2025. The broad index has now lost all of its post-election gains. The Nasdaq Composite, meanwhile, lost 0.35%, after dropping more than 2% at its lowest level in the trading day and at points coming close to correction territory. Tech stocks, meanwhile, are down 7% since Trump's inauguration. Premarket trading Wednesday was looking more positive. Follow live market updates.

2. Trump's speech

Trump addressed a joint session of Congress Tuesday night, promising to "rescue our economy and get dramatic and immediate relief to working families," by working to bring inflation down. He also used the speech to highlight his immigration policies, energy plans and his administration's efforts to end DEI programs in the government. As he spoke, several House Democrats held black-and-white signs that said, "Save Medicaid," and "Musk Steals," and Texas Democrat Rep. Al Green was ejected from the speech for heckling Trump and refusing to sit. Read more about Trump's speech, including his comments on taking control of Greenland and the Panama Canal, here.

3. Tariff talk

Trump acknowledged in his speech before Congress that his 25% tariffs on Canada and Mexico, and additional 10% tariffs on China, will cause "a little disturbance," but said it would be worth it. Trump's comments came hours after Commerce Secretary Howard Lutnick said the president would "probably" announce some kind of compromise deals on tariffs with Canada and Mexico on Wednesday, buoying markets. But Trump gave no indication during his speech that he was considering rolling back his just-imposed duties.

4. Industry warnings

Industries from retail to autos warned that Trump's tariffs will hit their businesses. Best Buy's CEO said price increases are "highly likely," noting that China and Mexico are the company's top two supply chain sources. Data and forecasting firm S&P Global Mobility, meanwhile, cautioned that roughly a third of vehicle production in North America could be cut by next week as a result of tariffs. Shipping giant Maersk's president of North America, Charles van der Steene, warned that "the short-term effect of any tariff clearly is inflation." And in the housing sector, the new tariffs could could raise builder costs anywhere from $7,500 to $10,000 per home, the National Association of Home Builders said, citing estimates from U.S. homebuilders.

5. Sneaker heads

Foot Locker warned that the retailer expects promotional pressures will weigh on its margins in the year ahead. The company improved profits in the all-important holiday quarter by more than 100% compared with the prior quarter, but it doesn't expect that to continue. Foot Locker forecast profits lower than Wall Street estimated, indicating pain in the coming year. Adidas, meanwhile, said its fourth-quarter sales topped expectations as the company sold off its final controversial Yeezy stock.

— CNBC's Alex Harring, Jesse Pound, Kevin Breuninger, Dan Mangan, Russell Leung, Michael Wayland, Diana Olick, Lori Ann LaRocco, Gabrielle Fonrouge and Karen Gilchrist contributed to this report.