Definition of 'Spoo'
A slang term for an S&P 500 contract that trades on the Chicago Mercantile Exchange (CME). The S&P 500 contracts trade on the CME independent of the S&P 500 index itself, and expire quarterly in the months of March, June, September and December.
The word originated in the XMI pit on the America Stock Exchange (AMEX) in New York. It comes from the symbol for the September contract: "SPU". Even though the name is based on the September contract symbol, the term is used to describe contracts of all expiries. When somebody speaks of the spoo, they are referring to the current, most active month trading.
Investopedia explains 'Spoo'
Trading a spoo is a bet on where the S&P 500 index will be at some point in the future, so these securities almost always trade at a premium to the fair value of the index. This is because of the assumption that the value of equities will rise as time progresses.