When news.com.au's James Law meets Australian entrepreneur Ed Robinson inside his 12th floor office a block away from New York's iconic Flatiron Building, he is wearing shorts and thongs.
You can take the boy out of Sydney but you can't take Sydney out of the boy, I guess.
Not only is it stinking hot in the city this time of year, Robinson is dressed down because he is celebrating.
The company he launched with his colleague Brandon Krieg in October 2015 has just finished its fifth funding round, amassing US$40 million from investors to bring the total capital raised since its inception to an impressive US$80m (NZ$107m). One insider has valued the company at US$240m, according to Business Insider.
The company, which created the investment app Stash, has grown at a head-spinning rate in 22 months.
It has had to move offices five times in seven months due to its burgeoning staff numbers and it is on track to have 1.5 million customers by the end of the year.
This start-up success story began with a simple money question back when Mr Robinson and Mr Krieg were both working for Macquarie Bank.
"We were literally sitting on the trading floor one day and one of our research analysts came over and said, 'Listen, I've got an extra $10,000. What should I be doing with it?' And a light literally went off in my mind," Robinson tells news.com.au.
It occurred to them that if someone who worked in finance was bewildered by the stock market, no wonder average Americans were intimidated.
"If this person who works full-time giving advice to funds and fund managers and huge endowments on how to trade and how to invest and what to buy, if they don't know what to do with $10,000, what does a Walmart employee do? What does an Uber driver do? What does your local FedEx deliveryman do?" Robinson says.
"We were like, 'Why aren't they investing?' because the best way to build long-term wealth is to invest it, to save it in something that's going to beat inflation, because if you don't you're then always going to be falling that little bit behind."
In researching these questions they discovered that average Americans were paralysed by their lack of financial literacy and were stuck in a cycle of debt. Robinson cites a scary statistic from Bankrate.com that 63 per cent of Americans can't pull together $500 in an emergency.
Their research led them to conclude that there were three main reasons why average Americans had shunned investing in the stock market: they didn't know where to start; the terminology was confusing; and they believed they needed a lot of money to get started.
So, the colleagues came up with an idea that solved these problems: Stash, an app that allows Americans to invest as little as $5 to start the path towards building a nest egg.
The concept was to create a simple and fast process that would lower the barrier to entry for novice investors.
"You can literally sign up for Stash, have an opened account and buy your first investment while you're in the queue at Starbucks," Robinson says.
And the numbers show that the concept is working. There are now more than 900,000 Stash users in the US, a figure that grows by an average of 3500 a day. The average customer is a 29-year-old who invests $20 dollars a week. Eighty-nine per cent of users had never made a stock market investment before. Ten million money transfers have been processed since the product launched.
But the company is not suggesting that it is about to turn all of its users into Wall St moguls.
The ambition is much more modest - and powerful.
They have built into the business a strong focus on financial education and tips to empower customers to build good money-making habits.
The app allows customers to place their savings among their choice of 36 baskets with snappy names, such as Defending America (aerospace and defence stocks), Social Media Mania (Facebook, Snapchat) and Colossal China (Chinese businesses) to develop a low-risk, heavily diversified portfolio.
"The biggest thing is we wanted to make sure they were in investments they could hold forever," Robinson said.
"One of the things that Brandon and myself had to take on board was that we went from a world of institutional trading where everyone was about alpha generation and beating the market and getting really high returns; with our user base, a win for them is actually putting $10 away a week and investing that money, because they've never had that opportunity before."
So, it's less of a buy-and-sell marketplace and more of a supercharged savings scheme.
"These people aren't trying to get on the property market, we need to help them just get started. Getting them to get out of this vicious debt cycle and getting them to put $20 or even $50 bucks away each week, because if you do that now and you do it for five, 10, 20 years you're going to be in a much better position down the track," Robinson says.
The business is yet to turn a profit, but Robinson says his sights are set on perfecting the product, attracting new customers and helping them get ahead.
"It's a big gamble taking an idea where you're not going to be earning any income for a long time, especially because I was married and had a kid on the way [when he resigned from Macquarie]," Robinson says.
"So there definitely was a large risk factor, but we saw this opportunity and we knew that someone was going to catch onto this.
"Our view was that we just had to get to it and get started and at least give it a crack because I would always regret it if I didn't. And so we took the gamble."
Robinson has built relationships with other entrepreneurs though the expat group Advance, and he encourages ambitious Australians to also take the leap overseas.
While the app is only available to US customers, there are plans to go international, and Australia is in Stash's sights.
But for now, Robinson says he is focused on getting the product right before "taking on the world".