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How far into the future is a stock future?  How do stock futures work?
Futures are an agreement to buy or sell something in the future.  The futures "price" is the price at which you agree to make the trade.  This price does not indicate what will happen in the future so much as it indicates the cost of buying the item today and holding it until the future date.  Hence, for very liquid products such as stock index futures, the futures price is a very simple function of today's stock index value and current short-term interest rates.  If the stock exchange is closed but the futures exchange is open, then using the futures price and interest rates one can back out an implied "fair value" for the index, which is in essence the market's estimate of what the stock index value would be right now if the stock market were open.  Of course, as soon as the stock exchange opens, the futures price trades to within a narrow band of the actual index value, where the size of the band depends on transaction costs (bid-ask spread, commissions, etc.).