Which company – just 4½ years old – is now the most valuable technology start-up in the world? It has just been valued at €37 billion ($45 billion), more than established companies on the Irish Stock Exchange such as Kerry Group (€10 billion), Ryanair (€13.5 billion) or Diageo (€36 billion)

A Silicon Valley company presumably? Maybe you would nominate Uber, the taxi-hailing app from San Francisco and now being rolled out in many cities worldwide?

Uber has been controversial for several reasons. Some regulated taxi drivers and their employers, and city and national governments, allege its business practices are illegal. Critics assert Uber places members of the public at risk since its drivers are unregulated. Some competitors have accused it of outright sabotage.

Despite complaints, litigation and outright bans in a private bidding process last month, Uber raised further funding that valued it at a massive €34 billion ($41 billion).

But Uber, at less than €37 billion, is not the most valuable start-up on the planet.

Actually the most valuable start-up is not American: Uber's closest American peers in value are Airbnb (an app for rental accommodation), Dropbox (a file- and document-sharing service) and SnapChat (a messaging app), with each valued during 2014 (according to the Wall Street Journal) at €8 billion ($10 billion).

Indian perhaps? Flipkart (an e-commerce site) is the most valuable Indian start-up, but – like Airbnb, Dropbox and SnapChat – is valued at a “mere” €8 billion.

So, if not American or Indian is it European?

At €3.3 billion ($4 billion) the most valuable European start-up is the Swedish company Spotify (a music streaming service) – not without its own controversies with certain artists because of the weak royalties it pays them. However, Spotify was founded in 2006 and is no longer early stage.

The highest-value European start-up less than five years old is Berlin-based Delivery Hero, an online food-ordering service with a network of 75,000 restaurants across 23 countries. Delivery Hero raised €300 million in March 2014, valuing it at €825 million ($1 billion)

So, at €37 billion, which then is the most valuable start-up worldwide?

Answer: Xiaomi in Beijing, founded in June 2010 by eight co-founders including chief executive Lei Jun (45). Xiaomi designs and manufactures Android smartphones, particularly for the Chinese and southeast Asian markets. After selling its very first phone in August 2011 it has become the world's third largest phone manufacturer, behind Apple in second place and Samsung in first.

Unlike its international competitors, Xiaomi sells its phones almost exclusively online. Lei Jun took an early decision to price Xiaomi phones at very little more than their manufacturing and component parts costs. However, models are normally sold for 18 months or so, and thus have slower release cycles for new phone versions than competitor phones. Consequently, Xiaomi benefits from falling bills for material costs over the lifetime of each model.

The company has relied heavily on word-of-mouth advertising via social networks rather than the expensive and glitzy marketing undertaken by some international competitors.

Can we ever expect an Irish start-up to join the global €1 billion-plus club? By “Irish start-up” I mean a company headquartered in Ireland, with most of its executive staff resident in Ireland, and a company less than five years old. While we all are proud of successful companies founded by Irish people overseas, a start-up operating from and controlled in Ireland is more likely to lead to jobs and wealth creation in Ireland.

I believe there is the executive talent and sales and marketing leadership to do so from Ireland, particularly given the internet’s global distribution and reach.

I also have little doubt that there are the technology and engineering capabilities to do so here.

The venture funding environment is reasonable, and very substantial sums are available internationally just waiting for the right business models and the right teams, regardless of geographic location.

Both Xiaomi and Uber illustrate the advantages of a reasonably uniform home market, in China and the United States respectively. But Delivery Hero and others – including our own Ryanair – show that even in the "common market", which in practice is still fragmented across the European Union, rapid international scaling is possible.

A prediction for 2015? I would like to think so.