Definition of 'S&P 500 Mini'
A derivative contract representing a designated fraction of the trading value of a standard S&P futures or options contract. Designed to expand the group of investors that could afford them, the S&P 500 Minis trade and act much like their pricier peers: the contracts are cash settled, follow the same expiration schedule and trade on the same stock exchanges.
Investopedia explains 'S&P 500 Mini'
S&P 500 Mini futures require margin on the part of the investor, while Mini options contracts are priced at 1/10 the value of the underlying S&P 500 index ($100 factor is equivalent to standard options contracts). The Mini futures contracts are marked-to-market daily, and expiration date pricing is determined by the opening price of the underlying index securities on the day of expiration.
Market demand for a product class like this developed as the S&P index grew from the 200-300 level in 1986 (when S&P 500 derivatives were first introduced) to more than 1,000 in 2007, effectively pricing individual investors out of the market as contract sizes grew to over $100,000. With the advent of the Mini, smaller investors can use the same hedging and speculation strategies available to institutional and accredited investors, and with high levels of liquidity and exchange-backed financial integrity.