This article from June 2017 seems to indicate that Saudi Aramco's IPO next year may be as low as 500 billion, while the Saudis are aiming as high as 2 trillion. So I'm a little skeptical of that 4.4 trillion dollar valuation in 2010 even accounting for inflation. Can anyone shed some light on this discrepancy?

Also, why isn't it in the infographic with the other modern companies? That's strange!