That's not a list of top shareholders (despite the headline). I think they only need to report the holdings of officers, directors, and anyone with more than 5%. Sean Parker does not fall into any of those categories, so they don't report his ownership.
While I don't know the specifics, it is very common for insiders to sell shares to new investors during later rounds. If I remember correctly, most of last year's goldman deal was from existing shareholders and not the company itself. So there is also a lot of opportunity to unload shares without using the formal markets as long as management is cooperative.
> it is very common for insiders to sell shares to new investors during later rounds.
Since when? Way back in the dark ages (2003), it was seen as a lack of faith in the company if the insiders were selling.
It is the paradox of the sale: If you think the stock is about to double or triple, why would you part with any of it? Sensible folks would go get a loan, esp with interest rates so low.
The idea is that by letting founders sell some of their stock early, investors and founders will be aligned and founders will be less likely to want or demand an earlier, safer exit that doesn't meet their investors' expectations. Basically, it lets founders get a few hundred K now so that they're more willing to try to go for broke later.
Founders Fund have even branded a share structure which allows easier conversion of co-founder (sometimes actually called Series FF) shares to shares of a later series sellable to investors in future rounds. I think that trying to grant early liquidity to founders has been common for at least two years and was a cause of major controversy during the Groupon IPO.
Since SOX? A perspective I've heard echoed by a few venture firms is that allowing insiders to sell a portion of the shares allows a bit of the pressure to come off and lets them focus on longer term value instead of wanting to rush into a liquidity event. Could be BS, who knows, but it's certainly happening.
A bird in the hand is still worth two in the bush, even if you're pretty sure you can get the two (or four) in the bush later.
Having been involved in a few startups where my equity was eventually valued at nothing, I'd certainly jump at the chance to sell some percentage of a future company I was involved with for real cash money even if I was pretty certain the stock might be worth more later.
1. http://techcrunch.com/2012/02/01/facebooks-s-1-and-the-large...