What it is:
How it works (Example):
An E-mini S&P 500 futures contract is valued using the following formula:
As the price of the S&P 500 fluctuates, the price of the S&P 500 E-mini futures contract fluctuates as well.
For example, if the S&P 500 is trading at 1200, the S&P 500 E-mini futures contract would be valued at $50 x 1200 = $60,000.
E-mini S&P 500 contracts expire on a normal quarterly schedule with expiration dates in March, June, September, and December of each year. E-mini contracts typically trade on the CME and they only trade electronically.
Why it Matters:
E-mini contracts are much more affordable to individual investors than regular sized stock index futures contracts. They also offer a way to trade outside of normal trading hours. In fact, the S&P 500 E-mini contract trades 23.5 hours a day.
E-minis can be more liquid than standard futures contracts and have lower commissions -- but they can also be more volatile. For these reasons, more E-minis trade on the S&P 500 than standard S&P 500 contracts.
Because they are only 1/5 the size of a standard futures contract, they only require 1/5 the margin to trade as well (note that margin requirements vary by broker, however, and with leverage comes risk).
[InvestingAnswers Guide: Everything You Need to Know About Trading Stock Market Futures in an]