Wall Street on Monday labored through a tough day to open the new trading year, which prompted CNBC’s Jim Cramer to break down the top investing themes he’ll be watching in 2021.

Investors should keep secular trends in mind because they are the best ways to approach a marketwide sell-off, the “Mad Money” host said after the major averages all closed down more than 1%.

“I always fall back on themes. That’s the best way to approach a sell-off, like we had today,” he said. “Themes are very useful if you’ve got some cash stockpiled after last year’s remarkable run.”

After wrapping up 2020 at or near all-time highs, the three averages declined sharply to open 2021. The Dow Jones Industrial Average fell almost 383 points, or 1.25%, to 30,223.89. The S&P 500 and Nasdaq Composite both dropped almost 1.5%, settling at 3,700.65 and 12,698.45, respectively.

Cramer said a mixture of the looming federal elections in Georgia to decide power in the Senate, profit-taking, uncertainty in Washington and a troubled coronavirus vaccine rollout in the U.S. contributed to Monday’s marketwide decline.

The decline, he suggests, created discounts in some stocks that investors can take advantage of.

“It’s these long-term themes that work the best. You can buy them tomorrow and then you can buy some more if they get knocked around the next day, and the next,” Cramer said. “The great thing about these theme stocks is they all do get cheaper as they go lower.”

Below are 10 themes and companies Cramer recommended investors to watch:

E-commerce

Travel and leisure

Digitization

Cybersecurity

5G

Stimulus

China

Wealth management

Remote work

Health care

Disclosure: Cramer’s charitable trust owns shares of Apple, CVS Health, Johnson & Johnson, Microsoft, Marvell Technology, Nvidia, Walmart, NortonLifeLock, Mastercard, Goldman Sachs, Salesforce.com, Boeing, Amazon and Costco.

Disclaimer