If it was possible, annualized gains from the stock market would be much higher than 7%. If there was a way to consistently get 100% YOY returns on an investment, someone would be getting rich on it. I'd happily pay someone 20% -- hell, 50% -- of the gains if they could get me 100% growth YOY. Instead, hedge funds have actually underperformed the S&P 500 over the past few years.
You are talking about something different (investing). Traders take a smaller amount of capital and earn a wage from it. So a talented trader might take $50k and over the course of a year working more than 40 hours per week, making thousands of trades over the course of the year, make a net profit of $60k. That $60k is not compounded. It pays for rent, food, beer.
Think of it this way:
How much can a trader make on a capital of $50k? Answer: $60k
How much can a trader make on a capital of $500k? Answer: $60k
Not literally, but hopefully that paints the picture.
But compounding gains for a 100% return on a portfolio is very possible, through more active trading.