A woman wears a face mask in the part of the city near neighbourhoods known for burning coal for heating in Ulaanbaatar, Mongolia January 26, 2017. Not many people in Ulaanbaatar wear masks to protect themselves against pollution. (Photo by B. Rentsendorj/Reuters)

In this image made available by France's Marine Nationale, the cargo ship TK Bremen sits stranded on a beach near Erdeven, France, on December 16, 2011, spilled fuel oil fouling the water. (AP Photo/Mael Prigent, Marine Nationale)

People celebrate the traditional Fiesta de las Aguedas on February 6, 2022 in Andavias, Zamora, Castilla y Leon, Spain. This celebration, also known as “El dia de las mujeres”, is a deep-rooted tradition in Castilla y Leon, especially in rural areas. The day of the Aguedas has its origin in the cult of Santa Agueda, and is celebrated every February 5. (Photo By Emilio Fraile/Europa Press via Getty Images)

A mannequin's head is covered in a woman dress shop in Kabul, Afghanistan, Monday, December 26, 2022. Under the Taliban, the mannequins in women's dress shops across the Afghan capital Kabul are a haunting sight, their heads cloaked in cloth sacks or wrapped in black plastic bags. The hooded mannequins are one symbol of the Taliban's puritanical rule over Afghanistan. (Photo by Ebrahim Noroozi/AP Photo)

A macaque climbs on a visitor at Phra Prang Sam Yot temple in Lopburi, Thailand on February 25, 2024. Although the thousands of macaques living in town are a tourists' attraction, many complain that they harass residents and damage houses and businesses while deterring potential visitors. (Photo by Valeria Mongelli/Anadolu via Getty Images)

Girls hold hands as they help each other wade through a flooded street after the passing of Hurricane Matthew in Les Cayes, Haiti, Thursday, October 6, 2016. Two days after the storm rampaged across the country's remote southwestern peninsula, authorities and aid workers still lack a clear picture of what they fear is the country's biggest disaster in years. (Photo by Dieu Nalio Chery/AP Photo)

Some are in it just for the money, others to help buy a meal. Then there are those who trade for fun or to spend time among friends. Millions of investors – pensioners, security guards, high-school students – dominate China's stock markets, conducting about 80 percent of all trades. Retirees gather in brokerage houses dotted around China also to enjoy some company and savour the air conditioning on hot days. Some start as young as 13, trading from home with an eye on future careers in finance. Winning isn't guaranteed. This year, among the most turbulent in China's financial history, its stock markets more than doubled in the six months to May, only to crash amid concerns that growth in the country, which makes everything from cars to steel, is slowing faster than previously thought. (Photo by Aly Song/Reuters)

Jenifer Lopez, 12, watches television at her home in Havana January 9, 2015. (Photo by Alexandre Meneghini/Reuters)