In the real world you wouldn't always buy / sell at the price you hit, someone could front run or by the time your sell hits the market there could be lack of b

In the real world you wouldn't always buy / sell at the price you hit, someone could front run or by the time your sell hits the market there could be lack of buyers and the price will have tanked. So this makes it seem easy, when the trade differ in real life from what might look available one minute.