The Australian model joined Evan, his Snap Inc. co-founder Bobby Murphy and other members of staff at the New York Stock Exchange on Thursday to support them as they took the technology brand public.

The 33-year-old covered the IPO on the messaging app, sharing pictures of Evan and Bobby ringing the opening bell to mark the start of the day's trading, traders on the floor, the stock exchange adorned with Snap Inc. logos and a group selfie in which she used the Snapchat animal filters.

Beside a picture of Evan near the Snap Inc. vending machine, she wrote on Instagram, "Congratulations to my love and Snap Inc," with an emoji of a face with love heart eyes.

The company enjoyed a successful opening day. They had a guide price of $17 (£14) a share but they opened with $24 (£20) and finished the day's trading with stock of $24.48 (£19.97), giving Snap Inc. a market value of $28.3 billion and putting Evan and Bobby into the top tier of technology billionaires.

Miranda, who got engaged to the 26-year-old Snap Inc. chief executive last year (16), is a vocal supporter and avid user of Snapchat and in a recent interview with The Times she denounced its social media competitor Facebook for allegedly copying Snapchat's features.

"I cannot stand Facebook," she said. "Can they not be innovative? Do they have to steal all of my partner's ideas? I'm so appalled by that... When you directly copy someone, that's not innovation. It's a disgrace. How do they sleep at night?"

During that interview, she also revealed the couple are abstaining from sex until they get married later this year (17) because Evan has very traditional views on sex before marriage.