Negative quantity in Stock

How to deal with such a situation. For example, the remaining stock of a product in the warehouse is 100 pieces. But the buyer wants to buy 150. This is not a problem for us, but simply a signal that the warehouse needs to be replenished with 50 pieces. That is, even with a balance of 100 pieces, the buyer can place an order for 150 pieces and the balance in the warehouse should be displayed as -50.