It was a direct listing. If insiders didn't sell their shares, there wouldn't be any to trade. He sold a very small fraction of his overall holdings.
Having to dump large amounts as if it's a given is something banks tell startups so they can get the equity themselves for a price they like.
This doesn't make sense. All of the shares are available to trade as soon as the DPO happens, regardless of whether or not they exchange hands. People who want them are free to place limit orders, and if those limit orders remain unfilled, they are free to raise them until the price is attractive enough for sellers to fill.
In this way, a natural equilibrium is reached where buyer and seller are both happy and engage in a trade. It doesn't take some mandatory or pre-stipulated "having to sell some amount".
Anything that would attempt to influence holders to sell under the premise that they "need to sell something" to "create a market" doesn't make sense, and typically serves the interest of the people saying it.
There's no reason such high early liquidity is mandatory.
My point is that the idea that some people "must" sell shares for there to be a market is false. "Must" implies: regardless of price.
If sales are not sold at opening-market prices, what happens is that offer prices increase until they are attractive enough to be filled.
This is a fill by mutual market price-discovery interest, rather than a fill by obligation. ("Must.")
My point is that "must" is incorrect, because even without it, trades would take place.
The idea that some group of insiders need to agree to liquidate no matter what on the first day is wrong, because natural market dynamics would incentivize it to happen anyway.
This is literally exactly what happens in a direct listing. There is no obligation anywhere. Each person selling is selling because the price offered is attractive to them.
It's not that a group of insiders has to liquidate because there's a DPO. It's that there's a DPO because a group of insiders wants to liquidate.