SPY and SPX give you exposure to the S&P 500, but these options have key differences you should know before getting started.

SPX does not pay a dividend, but SPY does. Dividends may not seem relevant because someone buying options does not own shares. You only receive the dividend if you own the shares before the ex-dividend date.

But the dividend is relevant for options traders. Some traders may exercise SPY options early to be on time for the dividend. An ex-dividend also lowers the stock price, which will affect your option’s value. If SPY offers a $1.60 dividend this quarter, SPY’s share price will decrease by $1.60 on the ex-dividend date. Options do not get adjusted downward proportionally to the ex-dividend, but a decrease in share price hurts calls and helps puts.

Traders can use two approaches for their options trading. SPY options use the American style of option trading, while SPX options use the European trading style.

Several factors influence an option’s cost, including the underlying asset’s price. Because the S&P 500 is roughly 10 times the price of SPY, the options for SPX require a higher investment. An investor would have to purchase 10 SPY calls with $400 strike prices to get the same exposure as one SPX call with a $4,000 strike price.

If a SPY option gets exercised, shares exchange hands. A call holder will receive 100 shares, while someone with a put can sell their 100 shares. Instead of letting traders exchange shares, SPX options involve cash. SPX options give traders the cash equivalent of their in-the-money profits plus the initial investment. If the option expires worthless, the trader gets nothing back.

SPY options follow the American trading style, which means options expire on Fridays at 4 p.m. Eastern. Some ETFs like SPY have multiple expiration dates each week, but most stocks expire after Friday’s close.

SPX options follow a different model, the European trading style. Most European options also expire on Friday’s close, but the third Friday of each month presents an exception. Options that expire on the third Friday don’t benefit from Friday’s price movements. These options stop trading after Thursday’s close. You cannot exercise a SPX option and have to wait for the settlement date to receive cash (SPX options do not involve shares changing hands), but you can exercise a SPY option at any time.

Options traders can only get involved with two types of contracts: calls and puts. These derivatives enable various options trading strategies you can use for SPY and SPX options. Both options let you engage in calls and puts.

SPX options hold a higher value than SPY options because of the difference in share prices. A trader needs 10 SPY options to have the same value as one SPX option. While SPX options hold more value per contract, they both produce similar returns. If the S&P 500 increases by 1%, the SPY will also increase by roughly 1%. A 1% increase in the underlying asset’s price will produce nearly identical percentage gains for SPX and SPY options.

SPX and SPY both have great liquidity. They are among the most in-demand options, with