Revellers take part in the the 70th Annual Columbus Day Parade in New York, October 13, 2014. (Photo by Eduardo Munoz/Reuters)

2016 Rio Olympics, Judo, Final, Women, 48 kg Bronze Medal Contests, Carioca Arena 2, Rio de Janeiro, Brazil on August 6, 2016. Otgontsetseg Galbadrakh (KAZ) of Kazakhstan and Dayaris Mestre Alvarez (CUB) of Cuba react. (Photo by Kai Pfaffenbach/Reuters)

Workers from the South Florida Science Center and Aquarium and Imagine Exhibitions put together an animatronic spinosaurus outside the science center in West Palm Beach, Fla., Tuesday, October 27, 2015. The giant spinosaurus is part of the Dinosaurs Around the World exhibit, set to open on November 1. (Photo by Maria Lorenzino/South Florida Sun-Sentinel via AP Photo)

In this composite image Actress Sophie Marceau has an embarrassing moment as her top falls down while she enters a screening of “Where the Truth Lies” at the Grand Theatre during the 58th International Cannes Film Festival May 13, 2005 in Cannes, France. (Photo by Pascal Le Segretain/Getty Images)

This picture taken with an underwater camera shows Japan' s Yumi Adachi competing in the Mixed Duet technical final during the synchronised swimming competition at the 2017 FINA World Championships in Budapest, on July 17, 2017. (Photo by Bernadett Szabo/Reuters)

This incredible panoramic photographs are distorted to create miniature worlds and terrifying tunnels. (Photo by Caters News)

Penelope Cruz attends the Palme d'Or Award Ceremony held at the Palais des Festivals during the 63rd Annual Cannes Film Festival on May 23, 2010 in Cannes, France. (Photo by Sean Gallup/Getty Images)

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)