Companies as a matter of periodic evaluation policy, or at times of acquisition, merger, or disposal want to evaluate the worth of the firm in question, and also private and institutional investors would like to evaluate the worth of the stock of the destination company. Such valuation can be done applying various recognized and widely used techniques, e.g. Capital Assets Pricing Model, Dividend Discount Model, and others.
What the Seller needs to start the work
In case of companies the data required are financial statements, and for investors in shares, the data are share prices, return, of the cf the company, and other bench-mark data which are available in net.