Oh...that the other order happened second kinda moots my line of inquiryThat was a limit order to sell 4300 at $18.85. On my broker website, I saw there was 43x100 on the bid side. I wanted to hit that bid with my order. It appears that my broker sent my order to ARCA and the 43x100 wasn't on that platform. But I've no idea why the trade happened at $8.85 instead. Right after my trade, another 1000 shares were sold at the exact same price. And that order was cancelled 56 minutes later. But mine wasn't.