Why the profile changes during the session

A GEX bar is not fixed. It depends on price, implied volatility, time left to expiry and new positions opened or closed during the day. That is why the 6:29 pm, 7:17 pm and 7:54 pm captures do not show the same values at the same strikes: the 7,624 strike goes from +$529M to +$2,970M in 85 minutes, 7,609 from +$118M to +$1,900M. Reading a profile once at the start of the session and carrying it in your head until the evening is the most common mistake with these tools. Here are the four engines that move it.