Buying a share for speculation: opposite for going short where the operation is that of selling. Speculators who long or short positions do not actually buy or sell shares, nor do they have any intention of doing so.
Someone who expects a futures price to increase over a given period of time can seek to profit by buying futures contracts. The futures contract can later be sold for the higher price, yielding profits. Because of leverage, the gain or loss may be greater than the initial margin deposit.
A purchase of a security that creates a "long position." The opposite of going long is "going short," when investors sell a security they do not own and hence, a short position is created. See: Going Short; Long Position; Short Position