Half stock means that if the standard value of a stock is 10 Rs then half stock’s value will be Rs 5. The par value of the stock is not very important in the context of a common stock. Hence the value remains the same in case of a regular stock and half stock.
The half stock’s importance is realised on the preferred stock in which a constant dividend needs to be given on the par value of the stock.
Also preferred stock has a higher claim than common stock in case of liquidation of assets typically equivalent to its par value. This means that a half stock would receive less amount in the event of liquidation.