The open is very volatile, and if you trade it, you need an extremely fast and responsive platform, which I have. It allows a spread of bids to be dropped over any range, any share quantities, on one-click, with no automation, in 1/10the of a second. All bids are removed on one click, with equal speed if a re-set is needed.
It's the only way to trade "chaos," especially on scary Dow drop days, like in March 2020.
Generally, since MM and brokerage algos are not that original, 10am and 11am are "known tops," 10:30 is a known trough. Always either 10am or 11am will be a top, so if 10am is not, you can bank that 11am will be.
I always enter the session expecting a 10am top if the Dow futures are friendly (green), and a walkdown to 10am when red (almost always on Mon-Tue, accumulation days, where news freezes traders, then they sell down quick, get the panic started, accumulate and flip back into the market). In short, if 10am is a drop, 11am will be a top. Both are also often tops.
Open breakouts shoot up because there's little resistance of sell orders stacked above the open price, so a quick buy up by MMs catches everyone sleeping, getting them to chase, fueling the pre-planned "launch."