Looking for the next big thing in tech stocks? Check out this under-the-radar company with massive growth potential. A few tech stocks have made plenty of millionaires. If you invested just $1,000 in Apple (AAPL -2.91%) stock 40 years ago, you'd have a total return of $2.7 million today. Placing the same $1,000 on the Microsoft (MSFT -2.23%) IPO two years later would have yielded a $7.1 million return. Those are life-changing returns. These millionaire-maker stocks have a few things in common. Apple and Mic ...