Silver and gold futures fell sharply Monday after the Chicago Mercantile Exchange, one of the world’s largest trading floors for commodities, asked traders to put up more cash to make bets on precious metals with prices surging this year.

This year, gold futures are up 65% and silver has more than doubled.

The CME raised margin requirements for gold, silver and other metals in a notice posted to the exchange’s website Friday. These notices require traders to put up more cash on their bets in order to insure against the possibility that the trader will default when they take delivery of the contract.

Exchanges sometimes boost margin requirements when a commodity or other security goes on a significant run. In its notice, the CME said it was raising margin requirements “per the normal review of market volatility.”

Silver futures tumbled 8% early Monday while gold slid 5%.

Protests erupt in Iran over currency’s plunge

Iran’s largest protests in three years erupted Monday after the country’s currency plummeted to a record low against the U.S. dollar, and the head of the Central Bank resigned.

State TV reported the resignation of Mohammad Reza Farzin, while traders and shopkeepers rallied in Saadi Street in downtown Tehran as well as in the Shush neighborhood near Tehran’s main Grand Bazaar. Merchants at the market played a crucial role in the 1979 Islamic Revolution that ousted the monarchy and brought Islamists to power.

The official IRNA news agency confirmed the protests. Witnesses reported similar rallies in other major cities including Isfahan in central Iran, Shiraz in the south and Mashhad in the northeast. In some places in Tehran, police fired tear gas to disperse protesters.

Monday’s protests were the biggest since 2022, when the death of 22-year-old Mahsa Jina Amini in police custody triggered nationwide demonstrations. She was arrested by the country’s morality police for allegedly not wearing her hijab properly.

Witnesses told The Associated Press that traders shut their shops Monday and asked others to do the same. The semiofficial ILNA news agency said many businesses stopped trading even though some kept their shops open.

On Sunday, protests were limited to two major mobile markets in downtown Tehran, where the demonstrators chanted anti-government slogans.

Iran’s rial on Sunday plunged to 1.42 million to the dollar. On Monday, it traded at 1.38 million to the dollar.