A prominent Saudi billionaire poured more than $500 million into Russia’s top state-linked energy firms this year around the same time as the Kremlin launched its brutal invasion of Ukraine, a stock exchange filing showed.

Kingdom Holding, the Saudi firm founded by Prince Alwaleed Bin Talal, bought the equivalent of $365 million in depositary receipts for Russia’s Gazprom in a transaction that took place sometime in February, according to the filings.

Alwaleed’s firm also dumped $52 million into Rosneft in February. In a trade that took place between February and March, Kingdom also invested $109 million in Lukoil’s US-based depository receipts, which represent a foreign company’s publicly traded stock.

The filings did not reveal the reason for the investments.

However, the Saudi billionaire bet on Russian firms at the same time that the Ukraine invasion prompted Western nations to enact sweeping economic sanctions against the Kremlin and Western-based firms to leave Russia in droves.

The stakes have plummeted in value as the sanctions caused lasting damage to the Russian stock market and economy.

Saudi Arabia and Russia have deep ties in the global energy market. OPEC+, a collective consisting of members of the OPEC oil cartel and other allied nations including Russia, has resisted calls to boost oil production to meet strong demand over the last year.

Kingdom’s investment in the Russian firms was first reported by Bloomberg, which noted the Saudi firm did not respond to inquiries as to whether it still held the investments.

The stock exchange filing also revealed that Kingdom invested in Chinese firms Tencent and Alibaba in 2021.

Alwaleed is one of the world’s richest individuals, with an estimated personal fortune of $16.9 billion, according to the Bloomberg Billionaires Index. His firm holds stakes in several US-based companies, including Snap, Twitter, Uber and Lyft.

Saudi Arabia’s sovereign wealth fund, which is led by Crown Prince Mohammed bin Salman, holds a 16.9% stake in Kingdom Holding, according to Bloomberg.

Oil giant Saudi Aramco earned a whopping $88 billion over the first half of this year as global shortages and shipment disruptions resulted in surging prices per barrel. The firm said its profits jumped 90% in the second quarter year-over-year.

Meanwhile, Russia has continued to yield massive profits from its oil and gas industry during the Ukraine war. While the US and many Western firms ended purchases of Russian oil, Europe remains heavily reliant on Russian energy.