Dejan,
News reports will say the FTSE 100 ended the day 20 points higher, while the DOW finished 30 points higher, for example.
These are referring to the “cash” markets indices, ie the FTSE and DOW indices are composed of underlying stocks. Similarly for the DAX and Stoxx indices.
To hedge the risk in holding constituent stocks (most) cash indices have a future. If you feel the market is due for a dive, but don’t want to sell your stock (for numerous reasons), you would sell (short) a future. If the market sold off 500 points, your portfolio would take a hit but this would be offset by the corresponding gain in the short future (you would have sold the future at 5000, the price reaches 4,500, and you buy it back (close) at 4,500. Because you sold it for more than it is now worth (500 points), this is your profit which offsets the 500 point loss on your portfolio).
Simple example of the valuation of a cash index. Assume an index is composed of two (constituent) stocks, ABC priced at 100 and XYZ at 200. The index value then equals, 100 + 200 = 300. As the prices fluctuate, so does the index. This is a “price-weighted” index. The FTSE is a “capitalisation-weighted” index, ie the greater the market capitalisation of a constituent, the greater its weighting or representation in the index. The DOW is price-weighted, S&P 500 is cap-weighted, DAX is cap-weighted but with provisions which I don’t understand. The (DJ Euro) Stoxx is beyond comprehension.
Theoretical values. Cash index at 7524. June future expires in 33 days, interest rate is 3.75%. Theoretical value of future equals = 7550: cash index x exp(interest rate x days/365). (The question of dividends is not that important, as far as I’m concerned. However, referring back to the Stoxx this is significant and occasionally leads to the future trading at what appears to be a discount to cash.)
Conversely, cash = future / exp(interest rate x days/365).
If these prices differed significantly from the theoretical values there would be potential arbitrage.
Grant.