> How do they come up with this?

You mean the valuation? It's a simple formula of ([money raised] / [shares issued]) * [total shares outstanding]

Just a linear regress on what they raised so far?

Ok, fair enough. feels overvalued though.

No, gruez was talking about how to take the new cash infusion and turn it into market cap. Literally just price of new share times share outstanding. You wanted to know how they decided on the market cap to accept money for. It's a totally different, complex, and non-public process.