Investing in the stock market can seem complicated, but one of the simplest and most effective strategies is to buy an ETF that tracks the S&P 500. ETFs like the SPDR S&P 500 ETF allow investors to own shares in 500 of the largest U.S. companies with just one trading transaction. This diversified approach spreads risk and increases the potential for long-term growth. What’s better than an S&P 500 ETF is knowing the seasonal window, which shows that the ETF has risen 100% for the past 15 years. Over time, it’s been difficult for individual traders and managed money to outperform the S&P 500 con…