Slippage: Market prices can change rapidly, especially during high volatility or low liquidity, resulting in a small difference between the expected price and the executed price.

Spread: Charts often display the mid-price (between the bid and ask), while your order executes at the ask (for buys) or bid (for sells). This means the execution price may naturally differ from the chart.

Order Type: Market orders execute at the best available price, which can differ slightly from the chart at the moment of execution. Limit and stop orders may also trigger at different levels depending on market movement.