the intention to offer a benchmark for investment funds, in November
1995 the Austrian Futures and Options Exchange ÍTOB introduced the ATX
50. The index is sampled in such a way as to represent the portfolio
of investible Austrian stocks.
The index sample comprises all 22 ATX
stocks plus another 28 stocks from a consecutive ranking by attractiveness.
Altogether the index constituents represent 84% of the total capitalization
of the official market segment and 97% of total stock market turnover.
Like the other members of the ATX index
family, the index has been constructed as capitalization-weighted value
ratios with daily chaining. A free float factor reduces the index relevant
market capitalization of individual stocks by 50% if the free float
of the particular stocks is less than 25% of total outstanding capital.