The 7% ownership also allows YC Continuity to be more attractive to later stage companies. If YC already has a 7% stake, then it only needs to invest an additional post-money 13% in order to raise its ownership to 20%. A new firm coming to the cap table would want to invest 20% post-money. So, if the company doesn't need 20% capital, then YC Continuity has a significant advantage.
Paper gains are notoriously easy to stretch.
My point was that GAAP is probably the best we're going to do because of the consistency problems.
The moment you start applying special rules or caveats per company you stop being able to compare companies properly as an investor, at which point the measure becomes useless as a talking point as well as being useless for tax calculations.
My original post was framed against tax because it doesn't really make a difference. If the new method is good enough for comparison between companies it's good enough to replace GAAP - unless it's not.
Like with YC they are US based and if they sell their dropbox stake they'll be taxed but more tax avoiding companies might say have held the dropbox stake through a Cayman Islands trust or some such and try avoiding it. I'd vote for something like for multinationals they do accounts as if all their multinational bits were in one country and then allocate the earnings to different countries in proportion to the sales there. So if Microsoft had a lot of Windows sales in Germany say they'd pay tax on the profits there rather than saying they were all generated at a DVD stamping plant in Ireland for example.
The main thing investors want are some measures that are reasonably forward looking, with the caveat that some of those forward-looking measures will of course be inaccurate when the future comes.
Taxes, on the other hand, should be mostly past looking, taking into account events that are fully settled and guaranteed.
If, as an investor, you're only examining trailing metrics, you're going to be a pretty horrible investor.
Unrealized gains on private, illiquid investments are neither earnings, nor cash flow.
https://www.iasplus.com/en/standards/ifrs/ifrs9
If I recall correctly, this prevents shenanigans where you over-represent the book value of assets that have lost value.
Thus, YCs GAAP ownership numbers would be nebulous. They probably use funding round valuations as the proxy, and that's commonplace for VC funds.