This year has proved a tough one for stock market debuts. But the year is poised to end on a high note, thanks to a software company born in Australia.

Atlassian, a maker of business development and collaboration software, priced its initial public offering at $21 a share on Thursday, above its expected price range of $19 to $20, and raising $462 million.

At the I.P.O. price, the company was valued at $4.38 billion, making it the fifth biggest company to go public this year, according to Renaissance Capital. The software maker’s last private investment round valued it at $3 billion.

The stock sale is a rare bright spot for companies looking to go public. Even prominent names have struggled to win the valuations that they had sought. That has chilled a once-heated market, with the number of I.P.O.s filed this year down 32.6 percent from the same time last year, according to data from Renaissance Capital.