If you're looking for a high-powered ETF with a history of earning significantly above-average returns, the Vanguard Information Technology ETF (VGT 0.29%) could potentially turn just $100 per month into $2 million or more over time. Over the last 10 years, the Vanguard Information Technology ETF has earned an average rate of return of more than 22% per year. Again, this ETF may or may not continue earning 22% average annual returns. So to play it safe, let's assume that going forward, you could earn either a 22%, 16%, or 11% average annual return. By starting early and investing consistently, the Vanguard Information Technology ETF could turn small monthly contributions into millions.