Thank you for your question. Yes, you are correct that traditional valuation methods are either irrelevant or impractical. The following are some general valuation truths, I have come up with after thinking about the equity valuation problem for quite some time. I'll expand on these in a later post. Suffice to say, some of these rules may seem obvious or intuitive, but like any mathematical definitions, articulating definitions can lead to some interesting and counterintuitive conclusions.
Definition #1: The value of a bankrupt company's stock = 0. Please note: I am using the term bankruptcy in a general sense, not in a legal sense. See the definition below.
Definition #2: The value of a non-bankrupt company's stock > 0.
Basically, assuming a company will not go bankrupt, about the only thing you can say about a company's valuation is that the stock price should be > 0. How much exactly > 0 should the valuation be? I don't know and nobody knows.
Definition #3: Bankruptcy is a function of a company's profits and assets as they relate to the company's liabilities, both financial and operational. Bankruptcy happens when a company does not generate enough profit to meet liabilities and/or the company's assets cannot cover due liabilities (e.g. those that hold liabilities against the firm refuse to "roll-over" these liabilities). It is important to note that bankruptcy, in the sense I am using it here, is not simply a function of financial debt. Any company can, in theory, go bankrupt, according to my definition, once they can no longer pay their bills, even if there is no financial debt.
Corollary #1: Expectations of bankruptcy (i.e. financial viability) lead to a change in the value of a stock. Any change in the value of a stock that is unrelated to issues of financial viability are simply noise and can be ignored.
Corollary #2: As expectations increase of bankruptcy the value of a company's stock will trend towards 0, and conversely as bankruptcy expectations decrease the value of a stock will trend away from 0;
Conclusion: You cannot determine the value of a stock (it is simply >0 or =0, as per above), but you can attempt to anticipate changes in the value of a stock. To anticipate changes, you must, analyze or react quickly to changes in expectations regarding the bankruptcy, i.e. financial viability, of a particular company.