• President Donald Trump's promised tariffs on Canada and Mexico take effect Tuesday.
• Target is out with fourth-quarter results — and a warning.
• Taiwan Semiconductor Manufacturing is putting up another $100 billion to support chip manufacturing in the U.S.

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

1. Wall Street woes

The Dow Jones Industrial Average shed 650 points Monday, the first trading day of the new month, as President Donald Trump vowed planned tariffs on Canada and Mexico would take effect. The Dow's drop made for a loss of nearly 1.5% on the session. The S&P 500 fell 1.75% Monday, its biggest loss since December, and the Nasdaq Composite fell 2.6%. Often-market-driving Nvidia fell more than 8% and is now down 15% so far this year. Follow live market updates.

2. Tariff Tuesday

President Donald Trump's promised tariffs on Canada and Mexico take effect Tuesday after hopes for a last-minute deal were dashed. The plan includes levies of 25% on imports from Canada and Mexico, as well as another 10% hike on goods from China after initiating an earlier 10% on that country last month. China has already retaliated, saying it would impose additional tariffs of up to 15% on some U.S. goods, including corn and soybeans, starting March 10. Canadian Prime Minister Justin Trudeau said his country would also put a 25% tariff on U.S. imports.

3. At your discretion

Target is out with fourth-quarter results — and a warning. The retailer beat on the top and bottom lines for its most recent period but said February sales were soft and its fiscal first quarter may be rough. Among the headwinds Targeted cited were unusually cold temperatures in January and uncertainty around tariffs. Target CEO Brian Cornell told CNBC that shoppers could start feeling the effects of tariffs, particularly on produce prices, in the coming days.

4. Upping the ante

Taiwan Semiconductor Manufacturing is putting up another $100 billion to support chip manufacturing in the U.S., funding five new fabrication facilities in Arizona. TSMC supplies semiconductors to companies like Nvidia and Apple for uses in AI and has been making strides to expand its U.S. footprint. The fresh capital brings TSMC's total U.S. investment to $165 billion.

5. American expansion

Foreign retailers are making their mark in America. International brands like Ireland's Primark, Spain's Mango and Japan's Uniqlo are increasingly looking to open new storefronts in the U.S., and not just in coastal cities. Nearly 30% of the roughly 19,000 U.S. retail locations opened between 2018 and 2023 were by foreign-owned brands, according to market research from GlobalData. "The U.S. is the number one consumer market," said Kevin Tulip, president of Primark U.S. "So to be here and to get it right means a lot. But you really need to get it right."

– CNBC's Alex Harring, Yun Li, Lisa Kailai Han, Kevin Breuninger, Evelyn Cheng, Gabrielle Fonrouge, Jacob Pramuk, Samantha Subin, Ryan Baker and Melissa Repko contributed to this report.