I would never, never, never use credit card debt or any borrowing instrument for investing in stocks. IMO, it is way too risky, even for a sure thing, and is the investment formula for personal economic disaster. It's a slippery slope that can result in high financial losses, high debt, personal ruin, bankruptcy and suicide. But that is only my opinion. I'm sure there are thsoe rare people who have done so successfully just as there are those who walk out of Vegas with more than a few bucks left in their pockets.