A partial execution means that only some of your order got filled. Partial executions occur when there aren’t enough shares to fill your order. Partial executions occur most commonly with limit orders placed on low-volume stocks.
In order for an order to execute, there has to be a buyer and seller on both sides of the trade. So, if there aren’t enough shares in the market at your limit price, it may take multiple trades to fill the entire order.
ABC stock is trading at $10.
You place an order to sell 1,000 shares of ABC at $11.
Your order is matched with a buyer willing to pay $11 for 400 shares.
Your order receives a partial execution of 400 shares instead of 1,000 shares because there weren’t enough shares available at your specified price of $11.