If you're hoping to make a killing in the stock market, and you're still carrying credit card debt, you're an idiot when it comes to personal finance. You might reasonably expect to make 8 to 10 percent on your investment in equities in the long term, but if you're carrying 18 to 20 percent debt on your credit cards, and paying finance charges or late fees, you're not doing the math right.

Besides, paying down debt at high interest rates is a sure thing, whereas investing involves risk.