Saudi Aramco's shares begin trading on the domestic stock market Tadawul on Wednesday, after the energy behemoth completed the world's biggest initial public offering. Saudi-owned broadcaster Al-Arabiya said the price of Aramco shares had risen by the maximum 10 percent in pre-trading orders, further raising the firm's valuation. Aramco has priced the IPO at 32 riyals ($8.53) per share, raising $25.6 billion by selling three billion shares and eclipsing Alibaba's $25 billion IPO of 2014 to become the world's largest.