Participants compete in the Mud Day Race extreme run competition at El Goloso military base, outside Madrid, Spain, June 11, 2016. Thousands of athletes got covered in mud as they celebrated International Mud Day running a 13-kilometer obstacle course on a sunny Saturday with heatwave-like temperatures up to a 29 degrees Celcius (around 84 degrees Fahrenheit). (Photo by Juan Medina/Reuters)

A 2020 Jeep Gladiator Rubicon is displayed during the Los Angeles Auto Show on Wednesday, November 28, 2018, in Los Angeles. (Photo by Chris Carlson/AP Photo)

A participant wearing his cosplay featuring a character from an animation gets his government contact tracing QR code in the “LeaveHomeSafe” COVID-19 mobile app scanned at Ani-Com and Games exhibition in Hong Kong, Friday, July 29, 2022. (Photo by Kin Cheung/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)

Meghan Puhr participates in a virtual realty presentation during an Intel news conference before CES International, Wednesday, January 4, 2017, in Las Vegas. (Photo by John Locher/AP Photo)

In this March 18, 2015 photo, a boy rides a mechanical bull for children at the Texcoco Fair on the outskirts of Mexico City. In Mexico, these types of fairs date back to Spanish colonial times, and in some smaller communities they are organized around the feast days of Roman Catholic saints. (Photo by Eduardo Verdugo/AP Photo)

A couple watches the sunset over a sea of fog covering the Geneva Lake from Chardonne, Switzerland, 28 December 2015. (Photo by Jean-Christophe Bott/EPA)

An aerial view of the figure of a Catrina skull made with 18,000 Cempasuchil flowers (Mexican marigold) is on display at the Church of Santa Prisca as part of Day of the Dead celebrations, in Taxco, Mexico on October 27, 2021. (Photo by Daniel Cardenas/Anadolu Agency via Getty Images)