In one aspect, a bi-directional foldable stock for a firearm may include a stock-to-firearm adaptor configured to be an interface to connect the firearm and the stock. The adaptor may include a base and a movable top portion that is pivotally and detachably engaged with the base. The top portion is attached to the firearm while the base is connected to the stock. The base with the stock is configured to pivotally rotate either in a clockwise or counter-clockwise manner to fold the stock on either sides of the firearm.