Not sure what you mean, the DOW is not cap weighted. If you just mean the biggest company, go the MSN moneycentral, type in each symbol and look at the market capitalization. THe component that creates the most price movement in the dow will be the stock which is most volatile for the period concerned. HOpe this helps.
And I thought since they are all equally weighted (since it is price based) that none of them stood out. Good to know!!!
This is pretty informative. http://www.investopedia.com/articles/02/082702.asp Some of the links within the paragraphs have good info. too.
The most heavily weighted component is United Technologies. The dow is nothing more than the sum of the latest prices divided by a divisor to get the cash value. So the stock with the highest price has the most influence. The divisor takes care of the rest. Go hear for complete details on components: http://www.indexarb.com/indexComponentWtsDJ.html