Get the DealBook newsletter to make sense of major business and policy headlines — and the power-brokers who shape them.__________The ranks of the richest people on the planet are no longer dominated by stuffy industrial tycoons and real estate barons with multigenerational empires.China minted two new billionaires each week last year, according to a study on wealth by the Swiss bank UBS and the consultancy PwC. And this is a younger, self-made Asian class that is redefining what it means to be ultra-wealthy.China added a net total of 55 new billionaires last year. (Actually 106 people in the country joined the superrich league during the period, but almost half of that amount also dropped off the list.) That brought the grand total of billionaires in the country to 373, or nearly one in five of the global total.Billionaire wealth in China has increased almost 40 percent, to $1.12 trillion year-on-year. Based on current rates of growth, Chinese billionaires will outnumber their American counterparts within four years.Technology is helping to line the pockets of many new Chinese billionaires — including Zhang Yiming of the video-sharing app ByteDance and Wang Jian, the co-founder of the Shenzhen-based gene sequencing company BGI. China is now producing almost as many unicorns, or companies worth at least $1 billion, as the United States.But China’s billionaires differ markedly from their global peers. With an average age of 55 years, they are almost a decade younger. They create wealth faster and take their companies public earlier; 17 percent of China’s new billionaires founded their businesses within the last ten years, more than twice as many as in the United States.Chinese billionaires are also bigger risk takers, which resulted in the high turnover in their ranks that saw 51 people lose the title there last year. As local authorities clamp down on corruption, China’s wealthy will also fear attracting too much scrutiny.