F OR YEARS investors dreamed of peering into the books of Saudi Aramco, the oil colossus wholly owned by Saudi Arabia. On April 1st they got their wish. A 469-page bond prospectus revealed $111bn in net income last year, more than the five oil majors—Royal Dutch Shell, ExxonMobil, Chevron, Total and BP —managed combined. The document also highlighted Aramco’s constraints.

Like rivals, it faces swinging oil prices and uncertain long-term demand. The bond will help finance the acquisition of 70% of SABIC , a petrochemical company, from the kingdom’s sovereign wealth fund, for $69bn. This will diversify Aramco’s revenues—and give the state cash to invest in sectors beyond oil (especially now that a planned listing of 5% of Aramco’s shares has been postponed).