This route allows you to invest in S&P 500 companies without relying too heavily on a select few.The S&P 500 is undoubtedly the stock market's most important index because it tracks the performance of around 500 of America's largest and most influential companies. After a disappointing 2022 when the index declined by over 19%, it has been on a strong bull run, up more than 78% since the start of 2023.This recent run is great news for investors who've been along for the ride, but it has also had another caut ...