That's known as unrealized capital gains, which is a totally normal thing to measure. But what's important is how the value is determined. With a company on the

That's known as unrealized capital gains, which is a totally normal thing to measure. But what's important is how the value is determined. With a company on the public market you theoretically have millions of actors constantly evaluating the price of something using the same information (10K, etc.). If it's a house you have an appraiser from the government to tell you what it's worth. These two examples are considered securities in the US and so everything is federally regulated. But when it comes to valuation of a private company you can pretty much do what you want (see: "community adjusted EBIDTA"). So it's totally possible for a company to be irresponsible and overvalue itself, to the extent where it might be considered fraud if the company ever went public.