This Opportunity Is a Nervous Investor's Dream

For example, an S&P 500 index fund will aim to match the performance of the S&P 500, which is an index comprised of the 500 largest trading companies by market capitalization. It should make you less nervous as an investor to invest in index funds because, while it's possible for them to decline in value, that generally only happens when the entire market takes a hit (especially when we're talking about S&P 500 index funds). Or to put it another way, with index funds, you won't end up kicking yourself for choosing one specific bad investment.