There's a lot of confused people in these threads. Steve Huffman sold 500,000 shares as part of the ipo, so they were some of the shares sold immediately before they opened on the market (at the about $30/share price). He still holds 4.1 million shares. Other insiders sold some shares as well. Some shares were created to raise money for the company. Once the ipo actually happens and the price for all those shares is negotiated with the bank assisting and all initial buyers, then it begins trading on the open market. At that point they are in a lockup period, and they can't sell anything for about 180 days. All of this is in sec filings, where you can see the source of all the shares that were part ot the ipo.
Look I hate Steve Huffman too, I'm here on lemmy after all. But this is a grossly over valued tech stock and there hasn't been many tech ipos in a while. It's very not surprising it would start sinking after an initial explosion of buying activity. It's not dropping from insiders unloading stock right now though. They're in lockup.