The S&P/ASX 200 Index is the most widely used index in Australia. In recent years, the ASX 200 has gained recognition as the “premier” index in Australia, over the All Ordinaries Index.
The index composition is highly dynamic and the number of shares in the index is constantly fluctuating, however the number of companies always reverts back to the “average” of 200. Currently there are 201 stocks in the index.
Have a question about the data? – FAQ
6 month, 1 year & 5 year ASX 200 Chart
All ASX Data is 20min Delayed (this includes Google, Yahoo etc)
Due to licensing restrictions imposed by the Australian Securities Exchange (ASX) – online share prices are 20 minutes delayed.
Access to “live” or “dynamic” share price data, requires an account with a Stockbroker or Financial Adviser.
Live share prices (click to refresh) – typically cost a retail investor about $10 per month.
Dynamic share prices (auto refresh) – typically cost a retail investor about $80 per month.
How does the ASX Open work?
Opening takes place at 10:00 am Sydney time and lasts for about 10 minutes.
ASX shares open in five groups, depending on the starting letter of their ASX code:
Group 1 10:00:00 am +/- 15 secs A-B, e.g. ANZ, BHP
Group 2 10:02:15 am +/- 15 secs C-F, e.g. CBA, DJS, EXT, FMG
Group 3 10:04:30 am +/- 15 secs G-M, e.g. GNC, HDF, ILU, JBH, KAR, LYC, MYR
Group 4 10:06:45 am +/- 15 secs N-R, e.g. NAB, OST, PDN, QAN, RIO
Group 5 10:09:00 am +/- 15 secs S-Z, e.g. SEK, TLS, UGL, VBA, WBC, ZIM
The opening time is randomly generated and occurs up to 15 seconds on either side of the times shown above, e.g. Group 1 may open at any time between 9:59:45 am and 10:00:15 am.
How does the ASX Close work?
Between 4:00 pm and 4:10 pm, shares go in to “match”. During the match phase – you can place, remove or amend an order, but no trade actually takes place.
Orders (both buy and sell) are ranked according to their respective price. Who ever bids the highest (for buyers) or offers the lowest (for sellers) is placed at the front of the queue. Often there is a crossover in the middle (e.g. the lowest seller might offer $1.55 and the highest buyer might bid $1.63). The area in the middle where they cross is called the “match”.
A random time is generated at 4:10 pm Sydney time, +/- 15sec. All “matching” share prices are weighted to find their mid-point, and this becomes the closing price of the share.
All trades on the close take place at the same price, regardless of what price you bid or offer.
Why do they do this?
Using a randomly generated time to open and close the ASX prevents stockbrokers and traders from manipulating the opening and closing price of a share. If all shares opened/closed at the exact same time each day, computers could be used to automatically place a trade at the precise moment a share opens/closes, thus “outwitting” human traders.
6 Month Chart
1 Year Chart
5 Year Chart
ASX 200 Listing Criteria
Like other Indices, stocks are primarily selected on the basis of their market capitalisation and liquidity. The effect each constituent has on the Index Value is proportional to the float-adjusted, weighted average of the relevant constituents market capitalisation.
A detailed summary of this process can be found in the Wikipedia entry:
The ASX 200 is market-capitalization weighted meaning that a company’s contribution to the index is relative to its total market value i.e. share price x number of tradable shares. The ASX 200 is also float adjusted meaning that the absolute numerical contribution to the index is relative to the stock’s value at the float of the stock.
Although the calculation starts with a sum of the market capitalisation of the constituent stocks, it is intended to reflect changes in share price, NOT market capitalisation. Therefore a fudge factor called the “Divisor” is used to ensure that the index value only changes when stock prices change, not whenever market capitalisation changes. For example, if a company increases its market capitalisation by issuing new shares, the Divisor is adjusted so that the ASX 200 index value does not change.
Want to know how you can invest in an ASX 200 Index Fund? Go to: ASX 200 Spider