Offer your thoughts or opinion on the input financial query or topic using your financial background.

What is the difference between trading and non-trading stock?
A non-trading stock or non-marketable security or unlisted security is one that does not trade continually on an exchange. For tax purposes, this can mean a whole new ball of wax which I would prefer the experts address with an edit to this answer or a new answer. For financial accounting purposes, this is when, say, one owns shares in an unlisted corporation and should be treated very carefully less one delude oneself. For trading stock, the value can be known immediately by checking any valid data provider's price and marking to market.  For non-trading stock, the value has to be "marked to model".  This can get one into Enron sized trouble. In this case, it's best to either leave the value of the stock at the purchase price and recognize gains upon sale, use a price from another honest transaction by third parties which are most likely difficult to attain, or to use some shorthand measure like applying the market P/E. Be wary of strangely high figures for value from the purchase price by using a market average, and don't throw away the shares just yet if a strangely low one arises.  This method can lead to strange results.