The advice former Wall Street executive Sallie Krawcheck would give her younger self about money

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If Sallie Krawcheck, a former Wall Street executive and founder and CEO of Ellevest, could go back and talk to her 30-year-old self about money, she'd advise her to do three simple things: Eliminate any credit card debt, contribute to her 401(k), and start investing.

In other words, she'd tell her to get her financial house in order.

"She's already gotten her credit card paid off, but if she hadn't, I'd zoom back in time and and grab her by the shoulders and say, 'What in the hell are you doing?!'" Krawcheck told Business Insider. "You need to pay off your credit card debt. If you can't afford something without credit card debt, do not buy it."

After paying off high-interest credit card debt — which Krawcheck believes should be taken care of as soon as humanly possible — she recommends planning for the future by investing and saving for retirement.

"Start investing in [your 401(k)] right away, particularly if there's a match at your company — that's called free money," she says. "And then begin to invest a portion of your income every time you get a paycheck in a diversified investment portfolio."

Even if you only have $100 to spare, it's still important to start investing early to take advantage of compound interest, which is when the interest earned on an investment earns interest on itself. That means a little money contributed today will ultimately earn more than a lot of money contributed tomorrow.

When you're young and in your 30s, the payoff from setting money aside for 20 or more years down the road can be a hard mental block to overcome. But as Krawcheck points out, it's an important investment in your future.

"You think, I'm in my 30s, who wants to save for retirement?" she says. "But [you're] also saving for buying a home, for starting your own business. Whatever that dream is that you have, begin to invest for it early."

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