&gt; It seems to me that stock price is correlated with more money: if I have X stock options worth Y dollars each, I effectively have X<i>Y dollars worth of stock<p>Sure, but the &quot;market&quot; price of stock isn&#x27;t really the value of </i>every* share, its roughly the marginal price of the last&#x2F;next share purchased or sold, but the more you want to trade, the farther from the market price the value will be.<p>And changes to the market clearing price don&#x27;t tell you about changes to the supply and demand curves, just where they intersect. So, for any but a small quantity of stock, you can&#x27;t tell what the real change in the realizable value of your holdings is just from the change in the market price, since there&#x27;s no guarantee that a change of $1 in market price equates to a change of $1&#x2F;share in the price you&#x27;ll get if you try to sell a particular quantity of a stock.<p>We tend to ignore that when placing a valuation on a portfolio because if you don&#x27;t ignore it, you can&#x27;t get a valuation. But those valuations are approximations, at best.