It's actually very simple: you buy low and sell high
Patrick and John Collison are still in their early twenties but they are well on their way to making a billion-euro-plus fortune. Envious? Me?
It was obvious that the Limerick boys would do well. Patrick won the Young Scientists' competition and then the brothers sold their first company Auctomatic for €2.3m. They were still teenagers at the time.
The Collisons moved to the US and the West Coast, a fertile ground for technology start-up companies. They set up Stripe.com, which may well revolutionise the way we pay for stuff on the internet.
They have attracted some Silicon Valley royalty as investors, including Elon Musk and Paypal founder Peter Thiel. The company simply kept growing and growing and a deal with Twitter could be a game-changer.
Another round of fundraising in January saw their Stripe.com valued at $1.75bn – in just three years. We assume the brothers have kept a majority stake. They have no plans to sell out and Stripe.com is only going one way.
The success of the Collisons has somewhat eclipsed that of many of their peers in the tech sector.
Terenure brothers Greg and Niall Turley sold a big stake in online car-rental business Cartrawler three years ago in a €110m deal. They wisely kept hold of a significant stake. The company is now being readied up for sale with a price tag of up to €300m. There have been other big exits in the sector including Now factory boss Tom Morrisroe, who sold his big data firm to IBM in a $100m deal last year.
The sale of John Griffin's UK-based car hire and rental business to private-equity group Carlyle for €357m saw him enter the Rich List as the highest new entry. Not bad for a job that started off as a nixer for the former accountant.
Vice Media's Shane Smith used to be a barman in the Baggot Inn in Dublin before he set up Vice Media, one of the most innovative media companies in the world. When Rupert Murdoch bought a stake, it valued the business at well over €1bn.
Animal healthcare and nutrition is something Irish people seem to have a real knack for doing. Pearse Lyons' wholly owned Alltech is in the middle of a spectacular growth spurt as it makes its way in China and Asia. The company may be set to more than double its revenues over the next year alone.
Lyons is joined on the list of big risers by Donal Tierney and his Bimeda group, which is sitting on astonishing amounts of money.
The US has been good for some Irish entrepreneurs. Seamus Mulligan merged his Azur Pharma drug company into Jazz Pharmaceuticals two years ago. The Nasdaq-listed shares have gone through the roof since then, adding €100m on to his already vast fortune. It's far more valuable than we thought last year.
In little over a decade, Michael and Brian Enright transformed a small Galway transport firm into the supercharged logistics group Syncreon. A €1bn sale was considered last year but the Enrights decided to hold on and raise money on bond markets instead.
Property barons are also making a comeback. We hugely underestimated the wealth of Galway's Comer brothers, who have been selling down a major supermarket and office block portfolio in Germany to fund a truly massive bet on the Irish economy. The Comers have been ploughing into the property market here, buying up anything that isn't nailed down. As asset values begin to rise, they are looking very shrewd indeed.
The wealth of the boom-time property developers is also back in focus, and on page 23 you will read Ronald Quinlan's analysis of the fortunes of the returning tycoons.
Disentangling their wealth from personal debt is tricky to do, and many of them – especially those using unlimited companies – have been left off the main Rich List.
However, we've hackled back at the wealth estimates of Northern Ireland's bigger developers as newer financial statements become available, detailing some eye-watering property writedowns.
Rising share prices have also boosted the wealth of some of the country's most well off. Ryanair's Michael O'Leary has not only become more cuddly but he's also become much richer as the low-cost carrier's share price rocketed over the last year.
Similarly, fortunes grew for the backers of Michael Chadwick's Grafton group, Eugene Murtagh's Kingspan and Owen Killian's bakery group Aryzta.
Weakness in the resources sector has hit the wealth of some of the country's richest people. Lion's rugby great and former billionaire Tony O'Reilly has seen his bank balance sapped by falling share prices since the economic crisis began. Last year, the O'Reilly wealth was dented further by falls in the share price of Providence Resources, in which he owns nearly 25 per cent.
Former Aer Lingus accountant and boss of Tullow Oil Aidan Heavey has also suffered at the hands of the stock market, with Tullow's share price falling by almost half over the last two years.
Retail has also suffered, as can be seen by the spate of examinerships and high-street casualties since the downturn began. We've trimmed back the value of Margaret Heffernan and the rest of the Dunnes Stores-owning family, as well as that of the Musgraves and Stafford family behind Lifestyle Sport.
However, other retailers are tearing up trees, with Charlie O'Loughlin's Euro 2 chain and Smyths Toys, owned by the Galway Smyth brothers, really expanding fast.
Renewables have fallen out of fashion somewhat. Eddie O'Connor's Mainstream Renewables was valued at well north of €550m last year. However, a funding deal saw Japanese trading house Marubeni pay €100m for 25 per cent, valuing the whole firm at €400m. O'Connor's majority stake was also diluted down.