Most profitable conversion of stock into money When Forbes-lists of top billionaires are published we are usually aghast of their riches and statements such as "the 8 richest people own as much as the poorer half" are disseminated.

I was wondering however, most of these top billionaires have a huge concentration of their wealth in the form of stocks/securities. Is this kind of wealth then calculated as "number of stocks possessed x latest stock price"? That would entail a subtle commitment/choice because of the reason that when a large shareholder such as a billionaire sells of his stake in a short period time (to consume the proceeds) this sudden excess of supply in shares deflates the stock-price thus rendering the total proceeds lower than the value previously proposed.

Q: is there a simple way to answer the question how large the proceedings can optimally be if a large shareholder wishes to liquidate his shares in a time-interval $T&gt;0$ (assuming something like a rational-markets hypothesis applies to all other parties)?
Yes.  There is a good chapter on this general question in The Valuation Handbook book by Ashok Abbott.  It is a whole chapter so it is too long reproduce here.

Shortened down, he shows that there is a half-life effect given the amount of volume that a dealer normally carries and how long it normally takes them to liquidate a position.

ISBN-10: 0470385790