Property investor Ross Makris, 39, knocked Queensland racehorse investor Nathan Tinkler off top spot on the magazine's 2009 list of the richest 100 Australians aged under 40 with self-made fortunes.

Mr Makris, who follows in the footsteps of his property magnate father Con Makris, is estimated to have personal wealth of $420 million, thanks to shrewd investments in retail properties.

Mr Tinkler slipped to third with $366 million, after topping the 2008 list with an estimated $441 million.

In second place this year was London-based hedge fund manager Greg Coffey with an estimated fortune of $390 million.

Mr Coffey, who once worked at Macquarie Bank, made headlines in 2008 when he walked away from hedge fund group GPG Partners and $US250 million in GLG shares to start his own hedge fund.

The impact of the economic downturn saw the combined wealth of the BRW Young Rich list fall by about 4.5 per cent to $5.8 billion and the cut-off for entry decline to $15 million, from $20 million.

BRW editor-in-chief Sean Aylmer said the fortunes of young Australian businessmen and women had proved to be fairly resilient through the financial crisis.

"What we find ... more so with the young rich is they seem to be nimble and entrepreneurial enough to avoid the worst of the crisis," he told AAP on Wednesday.

"There are 22 new names on the list and that's a big turnover, but you find a lot of these people, because they are so able to read trends and economies, they're pretty good at moving their money around and remaining rich."

The highest ranked woman was Tania Austin at number eight, who shares an estimated fortune of $156 million with partner Nigel Austin.

The pair established the Cotton On fashion group in Geelong in 1991, and the company now has over 450 stores and a number of niche offshoots.

There were just 13 women on the 2009 list, down from 14 last year, including actress Cate Blanchett (No.35, $53 million) and Sass & Bide fashion label owners Sarah-Jane Clarke and Heidi Middleton (No.53, $36 million).

London-based financier Lee Robinson led this year's list debutants with $150 million in assets.

The most notable departures from the list are Queenslanders Daniel Tzvetkoff and Sam Sciacca, whose online billing company Intabill went into liquidation.

The full 2009 BRW Young Rich List list will be published in the new edition the magazine out tomorrow.