The S&P 500 is an index of 500 large U.S. companies. The quoted figure moves with the prices of those stocks. On a quote screen it is labeled S&P 500, or SPX. No expiration month sits beside that number. The stocks trade as shares. A fund that holds them has its own share price.

The futures price is the line with a month

S&P 500 futures are a separate listing. CME Group lists the E-mini S&P 500 future under the ticker ES. The contract uses the S&P 500 as its reference and is quoted in index points. One contract is sized at 50 dollars times the index. The smallest move is 0.25 index points, which comes to 12.50 dollars. The futures line is the one marked ES together with a contract month. The index line has no month.

The two prices can differ on the same day. State Street's education page describes the futures price as the index level plus a financing cost minus expected dividends, so the futures price can sit above or below the index. A fund share priced above or below the value of the stocks inside it is a separate difference.

A contract ends on the third Friday

An ES contract stops trading on the third Friday of its contract month. CME settles it in cash. The settlement price is a special opening price of the stocks in the index that morning, called the Special Opening Quotation. The 500 shares are not delivered.

Sources

  • CME Group, E-mini S&P 500 contract specifications, underlying index and electronic contract, CME
  • CME Group specification sheet, 50-dollar multiplier, 0.25-point tick, cash settlement to the Special Opening Quotation, PDF
  • State Street Global Advisors, ETFs versus futures, cash index versus the futures price, SSGA