> its odd to me that the market can arbitrarily decide not to fill a sale at a listed price. You might be misinterpreting what the "listed price" actually is o

> its odd to me that the market can arbitrarily decide not to fill a sale at a listed price. You might be misinterpreting what the "listed price" actually is on a stock market. Prices that you see quoted are generally not prices that somebody is offering to sell at; they are the price that the last sale was made at. But that sale has already executed, so you cannot infer that there is someone else still willing to sell at that price. The only way to find out for sure what is available at what price is to place a buy order, and your buy order is not guaranteed to execute immediately because there might not be a matching sell order in the order book; it is not even guaranteed to execute as soon as there is a single matching sell order in the order book. It depends on the type of order and the exchange it is placed on and how orders and trades are reconciled. It's not like going into a store and taking an item to the cashier and buying it at the advertised price.