An “oligopoly” is a form of market in which a business or industry is run by a minor number of sellers also known as (oligopolies) (2). Oligopolies can give rise to many forms of collusion between dominant markets, which can reduce the degree of competition and lead to higher prices for buyers. The banking system is liquid and highly valued in the Australian financial sector. Over the past 10 years, Australia's top four banks have repeatedly shown how far they are willing to go to become the most successful bank. In recent times, the well-known Commonwealth Bank is now the second largest registered Australian institution in the market. the Australian Securities Exchange (ASX) in January 2008. Also noting that COM Bank achieved a market capitalization of AU79.86 billion at the end of the financial year (June 2011). (1)Rank Company Market capitalization1 Commonwealth Bank A$79.86 billion2 Westpac Banking Corporation A$65.62 billion3 Australia and New Zealand Banking Group A$56.25 billion4 National Australia Bank A$54.54 billionMore...