The S&P/ASX 200 is the Standard & Poor's stock market index used for benchmarking the performance of equities on the Australian Securities Exchange. The index was started on 31st March 2000 with a value listed at 3133.3. As of 31st August 2012, it has a value of 4316.10. The components of the ASX 200 do not always comprise of 200 stocks and can be dynamic. In general, the index is adjusted every quarter.