[glimshe]

Everything is valued by what people are willing to pay for it.

[cogman10]

The myth of the stock market was that value was tied to the performance or potential of the company whose ownership you were taking a part of.

[twiceaday]

Value is tied to how people assess value. They used to assess it on the performance or potential of the company whose ownership you were taking a part of. Now speculation plays a much bigger role. This seems predictably correlated with distance to last deep crash.