Saudi Arabia’s plan to open its $531 billion stock market to foreigners is prompting speculation that Islamic bonds will be next. The government’s approval of overseas financial institutions to trade equities may herald a similar relaxation of rules in the local-currency primary debt market. Opening the local-currency sukuk market would give foreign investors access to companies that sold 42 billion riyals ($11.2 billion) through a dozen sales in the past year. That’s more than three times the amount of dollar Islamic bond sales, which are open to overseas buyers. However, access to the kingdom’s debt market may appeal more to investors wanting to broaden their exposure than to those seeking yield since lots of Saudi debt prices very tightly.