It's the last of the grouping of the world's largest economies, the G20, to open up its market to foreigners. Until now, they were only able to indirectly buy shares and would only get the economic benefits.
Industry experts say Monday's move, that allows foreigners voting rights, could be transformative for the region as Saudi companies will be able to profit from the scrutiny and strategy of sophisticated international partners and overseas investment will help push forward the country's economic reforms.
But don't hold your breath. Major emerging market players are not quite queuing around the bourse yet.
That's because there are a multitude of rules to determine who can invest in the gradual opening-up of the Middle East's biggest stock market.
They appear to be quite restrictive. Only institutions that manage $5bn (£3.2bn) of assets (or $3bn if the regulator makes an exception) with a five-year investment record will be given the green light for now.
No single investor can own more than 5% of a company and overall foreign ownership of that company cannot top 49%. Overall, only 10% of equity in the stock exchange, called the Tadawul, can be foreign-owned.
Attractive market
Despite that, buying into the stock market - which is up 15% already this year - is a mouth-watering prospect for qualifying investors.
The market's value of over $560bn and daily trading volumes of about $2.4bn outstrips bourses in South Africa, Russia, Turkey and Mexico.
One key sector, retail, is booming due to high consumer spending.