Saudi Arabia just opened the Middle East's biggest stock market to global investors for the first time in history

Saudi Arabia just did something that Western investors have been pining for - the oil-rich nation has opened its stock market to the world.

Until now, Saudi stocks were restricted in ownership to just Saudis and citizens of the nearby Gulf states. Westerners could only get a slice of the action through exchange-traded funds and similar financial vehicles.

It's not just the biggest stock market in the Middle East, according to Bloomberg, it's bigger than all of the Gulf states' stock markets combined.

London Capital Group market analyst Ipek Ozkardeskaya called Saudi Arabia a "shiny new destination for investors looking to fly out of the European markets this week."

Lots of analysts have suggested that there are big opportunities for investors in Saudi Arabia.

But for now, ownership is still restricted to institutions with assets under management (AUM) of at least 18.75 billion Saudi riyals ($5 billion, £3.22 billion), so retail investors aren't invited to the party yet.

In a note in May, HSBC noted that Saudi Arabia could make up as much as 2% of MSCI's emerging market index, if the institution decided to include the country in its index. But if it was included as an MSCI frontier market, it would dominate the index, taking up about 44% of the total capitalisation.

Here's what the Tadawul index of Saudi stocks has looked like in recent years: