He got his break with Fay Richwhite in 1991.
"I was a doe-eyed kid from West Auckland and at that time it was the firm to work for."
They get a bad rap, he says.
"But guys like Michael Fay were visionaries."
On Hanover - where he worked for just seven months between May and November 2007 - he says he really doesn't know what happened after he left, but it was still in good shape while he was there.
"It was functioning, it had $90 million cash on the balance," he says.
"I think people need to be careful to distinguish between what happened with some individual companies and what happened to the sector ... the whole global finance and banking sector went into an unprecedented meltdown."
From there he moved to Tower Investments, where he was chief executive until that business was sold in 2013.
At 47 he retired.
It was something of a classic mid-life crisis, he says.
He's spent plenty of time since then surfing, practising yoga, meditating on life.
"I knew I would keep working - just not for money. What I wanted to do was work for love, not money," he says.
"I just got tired of looking in the mirror and thinking about going to work and making more money for shareholders. Especially when it wasn't necessarily in the interest of clients or members that you make more money."
I just got tired of looking in the mirror and thinking about going to work and making more money for shareholders.
He describes a kind of institutional cynicism that creeps in when you spend too long in the "belly of the machine".
"They're all well-meaning people," he says of his former colleagues in the industry.
"But they are locked into business models that demand more profit every quarter. I have no problem with the profit motive but if it gets to be an excess ...
"I think there is a social change and social awareness that's creeping in. Capitalism is changing ... the younger generation saying it's not enough to just make money."
At Tower Stubbs managed KiwiSaver for five years and watched its growth closely.
"It was pretty clear that the promise of KiwiSaver was coming to fruition in some ways as members saved more money than anyone ever expected," he says. "It became a very trusted brand - the Government and regulators deserve a lot of credit for that."
But over time the benefits of scale are supposed to pass through to the members first and foremost and partially to the providers, he says.
"It was working the other way around and almost no benefits of scale going to the members, all going to increased profits ... and extremely tempting profits because there is no capital costs involved."
Poor disclosure and a lack of competition on fees also bothered him.
"I just felt that part of the industry was developing in a very unfortunate way. If you did the numbers it was going to be really very, very large profits ... and there was a prism in the industry where no one had any interest in dropping fees." So it needed a disruptive model, he says.
"And there it was in the form of Vanguard."
Vanguard is a US cut-price funds manager which passively tracks stock indexes. It uses its scale and a not-for-profit model to keep fees to a minimum and has been a huge hit in the US. It now manages more than US$3.4 trillion in funds.
"What we're doing is taking a lot of what they're doing and bringing it here so it's nothing new."
Stubbs says his other revelation "after being in the belly of the machine" for all those years is that managing money really isn't that complicated.
"I've seen it all. I've managed derivatives and all sorts of structures like that - and actually the fundamentals about money are really simple. I think they want you to think it's hard so you'll pay them money."
As well as the big fee savings, Simplicity says it will deliver savers up to $65,000 compounded over a working life and it will put 15 per cent of management fees into related charity work such as improving financial literacy. And profits are reinvested to drive fees down further over time.
Stubbs has an infectious passion when he gets on a roll so it's a surprise to hear he has had to overcome a serious stutter.
"I had a very bad stutter as a kid and effectively couldn't talk ... couldn't use a telephone until I was about 23."
One of the biggest things he ever did was to take up debating.
"I was asked by a speech therapist to do public speaking and debating, which terrified the hell out of me, but something happened when I got up on stage and had an audience."
It's helped him negotiate his way through the business world and made him a pretty good salesman, he says.
"If I know a word I'm going to stutter on I have to think ahead to find a way around it ... so I developed a sort of verbal dexterity that allows me to talk and sell and I've probably been selling things ever since."
He was hungry to make it in the world and grew up "envious of kids that went to private schools".
But he wasn't necessarily headed for finance.
His first job was with IBM on computing, but when the opportunity came up to join Fay Richwhite it set him on a different path to banking jobs in London with NatWest and Goldman Sachs.
Otherwise he credits a lot of his success to a classic Kiwi childhood.
"My driver in this is my West Auckland roots," he says.
"You see that in the workplace when you are somewhere like London or New York. The New Zealanders are the ones that everyone loves working with, not because they are necessarily smarter but they are likeable and hands-on and helpful."
It would be a shame to see us lose that lifestyle advantage, he says.
"It's hard to quantify, you can't sit exams in this stuff ... it is the X-factor when you are in an interview. It's that bravery Kiwis have because as kids we're allowed to do stuff that other kids aren't. So I was so lucky having a West Auckland upbringing."
So now Stubbs is back in the game and hoping to cause a stir in his old industry.
He's unashamedly poking it with a stick and challenging rivals to tackle Simplicity head on.
"My guess is they'll do nothing and hope we go away," he says. "But there's a lot of good people behind us and we're not going away. I want to work for another 30 years.
He does feel it is a case of giving something back to the country.
"I guess it's no different to putting the time into being a rugby or netball coach. I'd be a lousy rugby coach but I'm OK at understanding money."
Sam Stubbs
• Age: 51
• School: Kelston Boys
• University: Auckland. MA political philosophy
• Career: IBM, Fay Richwhite, NatWest Markets, Goldman Sachs, Hanover Group and Tower
