Saudi Aramco became the world's most valuable listed company at $1.9 trillion, nearly $700 billion more than Apple, after its shares jumped 10% on their trading debut on Wednesday. The Saudi state-run oil company raised $25.6 billion in the world's largest Initial Public Offering (IPO) beating Alibaba's $25 billion listing in 2014. Aramco sold a 1.5% stake in the IPO.