Who is the wealthiest man in the world, Amancio Ortega or Bill Gates?

At 11am on Wednesday, Zara founder Amancio Ortega was the richest man in the world according to Forbes’s real-time ranking. But at 1.30pm, he had been pushed down to second spot by Microsoft creator Bill Gates. Then, at 4pm, the Spaniard rallied back to take the top position again.

The race between both billionaires to lead global wealth lists depends on how their shares are doing on the markets at any given point. Forbes uses a system that calculates how much an individual’s portfolio shares are worth. If shares go up, their fortune increases. If they go through a slump, a few millions are lost and the list order changes.

For a few hours in 2015, the Galician-born Ortega was the richest person in the world. But he was quickly replaced by Gates again, just hours later. So who is wealthier? It depends on how you count it, and no system is perfect.

On Wednesday, Forbes attributed a net worth of $78.5 billion to Gates, while Bloomberg, which also uses a real-time system, assigned him $90 billion.

As for Ortega, Forbes has him down as the richest with a net worth of $78.9 billion while Bloomberg puts him in second spot with $77.9 billion.

Forbes does not specify what assets it takes into account to make its calculations. Bloomberg does, in a very detailed way: in Ortega’s case, besides his nearly 60% stake in Inditex, the parent company of Zara and other popular fashion brands, he is assigned $7.1 billion for his real estate firm Ponte Gadea. This company is not listed, so its value is an estimate. Bloomberg also counts in Ortega’s favor a further $2.9 billion in other assets as well as a boat worth $8 million.

As for Gates, Bloomberg takes into account not just Microsoft, but also his investment firm Cascade as well as his stake in some 30 other companies, including photo agency Corbis.

Besides Ortega and Gates, other recurring names in the club of the world’s wealthiest are Amazon founder Jeff Bezos, investor Warren Buffet, Facebook creator Mark Zuckerberg, Mexican businessman Carlos Slim and Ikea founder Ingvar Kamprad.

English version by Susana Urra.