An options contract is a versatile financial derivative that gives the buyer the right, but not the obligation, to buy or sell an underlying asset—such as a stock, index, ETF, or currency—at a predetermined price (the strike price) within a specific time frame (until the expiration date).

If you're in your 20s or 30s and just starting to invest, the big question is often: ETFs or mutual funds — which one should I choose?