Australian tech phenomenon Atlassian will start trading on the US sharemarket overnight, valued at $US4.4 billion ($6 billion) in an IPO that will catapult its founders among the top 20 richest people in Australia. 
A flood of investor interest has set the software company's share price at $US21 when it hits the boards on the Nasdaq Friday morning. That's more than the price range of $US19 to $US20 Atlassian had targeted. 
The share sale, which raised $US462 million for the Sydney-based company, was heavily oversubscribed, setting the scene for further price gains when the stock starts trading, with investors who missed out in the float expected to pile in.  
Atlassian's founders, former University of NSW classmates Mike Cannon-Brookes and Scott Farquhar's retained 66 per cent stake in the business will be worth almost $US3 billion, placing them well in the top 20 on the BRW Rich List with an estimated wealth of more than $2.2 billion each, more than the estimated personal fortune of billionaires such as media magnate Kerry Stokes, retail king Solly Lew, investor Kerr Neilson and retailer Gerry Harvey at the last time the list was compiled.

Australian record
Atlassian, which was founded in 2002 and today employs about 1200 people, builds project management software and chat tools for businesses and counts Facebook, NASA, Visa, Netflix, eBay and Toyota among its clients. 
The $US4.4 billion IPO valuation blows away the $US3.3 billion at which the company was valued earlier this year when institutional investors including T Rowe bought shares from staff members. 
The investor run on Atlassian's shares gives hope to some of its peers that consider going public at a time when US tech listings have been met with skittishness.
But Atlassian stands out for being both profitable and not relying on venture capital to fund its growth. Its latest annual revenue stood at $US320 million, having grown by nearly 50 per cent each year, and the company posted a $6.8 million profit for the year to   June 30. 
The IPO was underwritten by Goldman Sachs and Morgan Stanley, and is the biggest llisting by an Australian tech company on record. 

No local call
Yet while the float beat all expectations in the US, there won't be much interest from Australian investors in the shares, says Alex Pollak, the chief executive of Loftus Peak whose fund invests in disruptive industries and holds shares in Google, Apple and Alibaba.
"In Atlassian's case, neither is the listing nor the largest part of the business in Australia," he said. "It will have its supporters here and there will be some institutions that have a look at it."
"But it won't be in the indexes here, it's an out of index bet. It won't get a lot of Aussie investor interests."
Funds specialised in Australian stocks usually have to invest in stocks listed on domestic share indexes.
Investors keen for a slice of the action however can bet on the company's market capitalisation on the close of its first day of trading.  Online broker IG is running a "grey market" on the float, in response to the big public interest in the company.
IG market strategist Evan Lucas said 90 per cent of participants in its grey market were bullish the company, with some expecting Atlassian to fly on its market debut, tipping a $US5.5 billion market cap at the close of trade.
Mr Lucas said the interest was on par with that of Nine Entertainment's float in late 2013, but well off the hype around Chinese ecommerce company Alibaba's 2014 listing.  
"The issue with Atlassian is [that] unless you know who they are or what they do, you won't be interested," Mr Lucas said. 
The people buying in the grey market were "tech heads" he said, who knew the Atlassian story well and wanted to get involved, he said.
. It was very difficult for retail investors to get a slice of the Atlassian pie because they listed in the US, and were domiciled in the UK. 
with John Kehoe