Why should I invest in index funds?

Index funds greatly reduce your investing risk. Rather than going all-in on a single bet, you can buy thousands of stocks and bonds in an index fund. You own each underlying stock or bond based on how much it’s worth, not on based on some “expert’s” guess. This lets you easily bet on the entire world economy, which is almost guaranteed to go up in the long run. 

More info: 3 Reasons to Invest in Index Funds