The BRW Young Rich list, has a new number one. Thirty-nine-year-old Ross Makris, an Adelaide-based property developer, increased his wealth by 13.5% to $420m in the last 12 months and now tops the list of Australians aged 40 and under.

In recent years, Makris has become increasingly independent from the family business, Makris Group, owned by his father. Makris owns, in his own right, a number of shopping centres and residential property projects in Adelaide. He also hopes to take advantage of the expected South Australian resources boom, having now secured six SA mining tenements.

Of the top 10 wealthiest young Australians, two are involved in property development, four in hedge funds, two in retail, one in mining and one in IT.

The combined wealth of the 100 people on the list has declined by 4.5% since 2008. The cut-off for entry to the list has also dropped, from $20m last year to $15m in 2009.