$100 x 10 = $1000, a ten bagger $1000 - $100 = $900 (your gain) or a gain of 900% a ten bagger is a 900% gain. You have to deduct your original investment because you didn't GAIN it, you already had it. Your profit is $900 or 900% above what you started with. http://www.investinganswers.com/financial-dictionary/stock-market/10-bagger-1332 10-Bagger What It Is: A 10-bagger is a stock thats value increases to 10 times its purchase price, or by 900%. How It Works/Example: If a company's stock is priced at $20 per share at the point of its IPO and increases in value to $200 after a year, it is a 10-bagger.