Take a look at the illustration below. It shows the market capitalization of the 10 top IT suppliers from this morning, in the wake of Wall St shedding over a trillion dollars of value. Of course, the tech sector is not the focus of the crash, but still considerable value has been lost.

If you want to compare pictures you can look at this bar chart (April/08) , this one (December/07) and .this one (Oct/Nov 07). A rough summary of the various companies is as follows:

The biggest falls in value (measured against the highest stock value in the last 12 months) have occurred with Yahoo! and Dell (both about 48%). The Yahoo! decline is easy to understand, since its stock price peaked with the Microsoft bid and Dell has been suffering for quite a while.

The next two biggest losers are Apple and Google (both having declined about 45%). Again this could be characterized as no surprise given that the stock prices for both companies were clearly persuming fast growth which neither company is now likely to achieve. Additionally Apple in the consumer market and Google in the advertising market are most likely to suffer revenue declines (or much slower growth) in the coming months.

The least declines were with SAP, IBM, Oracle and Hewlett-Packard, all of whom major in selling to the corporate market. So if the stock market is saying anything here, it’s saying that those revenues are less vulnerable than consumer revenues right now – and that seems sensible enough.

However, I doubt if the market is indicating much in a definite way. In a market as volatile as this, financial distress often forces stock holders to liquidate some of their holding in a “dash for cash”. This can happen unevenly and lead to value anomalies that right themselves in time.