Stock is a setting in Versus Mode in which the winner is the last player with remaining lives or "stock". In stock setting, the game allocates to each player a number of lives, which are depleted one by one each time the player is sent off the stage. A time limit can be put into a stock match via additional rules, with the player with the most number of stock winning when time runs out.
The word "stock" can also be used to describe each life: "We played with 4 stock." Stock setting with a time control is the standard setting for tournaments. It can also be used to indicate how much a player beat another, i.e. A says "I 4-stocked B" if A had 4 stock when he removed B's last life.
Stock are used to measure how many times a player can be K.O'd before they can no longer respawn, though in one player modes, they can Continue at the cost of some Coins and half their Points. They are measured by symbols directly above the player's Damage Percent. Stock can be set to anything from 1 to 99 in vs. matches and from 1 to 5 in Classic and Adventure modes. All-Star must be played with only one stock. The player, in Classic or All-Star mode, is given point bonuses depending on whether or not all of their stock remained intact by the end of the last round. The player is also given one stock to complete a target mini game, Board the Platforms, Snag the Trophy or Race to the Finish. Despite this, getting KO'd will not deduct a stock from the next round's total.
In all iterations of Super Smash Bros., stock is indicated by an icon located within the damage meter, with Smash 64, Melee, and Brawl placing the icon above, and SSBWU/3DS placing it below. In Smash 64, Melee, and SSBWU/3DS the icon is the character's head, while in Brawl it is a circular dot, though in The Subspace Emissary the stock system uses the character's head.