SHANGHAI • Earlier this year, Mr Xu Caiyuan watched helplessly as the numbers flashed across a computer screen at his office in Shanghai's glittering financial district. The Chinese stock market was in free fall again.
In a spectacular crash just months earlier, it had wiped out significant assets of professional investors like himself and the life savings of many ordinary citizens.
The instability spread to global markets.
"During the stock market plunge, many middle-class investors lost their money, and they don't know why," Mr Xu, 38, said over lunch recently. "The reason the market plummeted is that this is a man- made disaster."
Long a shareholder advocate, Mr Xu is now waging battle against a powerful government agency in hopes of punishing the officials he blames for the twin disasters, which shook world indexes in the summer of 2015 and this January.
During the stock market plunge, many middle-class investors lost their money, and they don't know why. The reason the market plummeted is that this is a man-made disaster.
'' MR XU CAIYUAN, who is waging battle against a powerful government agency in hopes of punishing the officials he blames for the disasters which shook world markets last year and this year.
His target is the China Securities Regulatory Commission, which has come under intense criticism from investors and some officials for withholding or misrepresenting information and enacting emergency trading controls that contributed to the terrible losses suffered by investors.
Its chairman Xiao Gang was fired from his post in February.
The market instability led analysts across the world and many investors in China to ask whether the Communist Party was properly managing the markets as well as the broader economy.
Mr Xu has emerged as the face of investor frustration as he tries to sue the agency.
Chinese news groups have published a stream of articles about Mr Xu this year, and several news sites have called him the "big brother helping to protect rights".
In person, Mr Xu does not look like a legal brawler.
A slim, short man, he showed up to lunch wearing hip glasses and a navy suit with white dots.
But as he pulled out documents related to his lawsuit and spoke about them in sharp bursts, his combative side became evident.
"I don't know if there will be justice, but I can choose to do things," he said. "The reason we appealed to the courts is we trust in the courts and the legal system."
A lower court and a high court rejected his lawsuit this year, despite the news media coverage.
In October, he filed an appeal with the Supreme People's Court, hoping the judges would force a lower court to hear the case.
He has been travelling between Shanghai and Beijing all year to deal with the courts, and now awaits an answer.
Lawyer Zhang Ren at the Beijing Century Law Firm, who has been advising Mr Xu, said the government's attempts to ignore the lawsuit "are embarrassing".
Mr Zhang said the case was one that could be a legal marker: "When China becomes more democratic and respects the rule of law, this could be a precedent."
Lawyer Liang Min disagreed, saying Mr Xu was pushing a "sensationalistic" case with no basis in proper administrative law.
Mr Xu comes from Wenzhou, in Zhejiang province in south-eastern China, which is known as a hotbed of entrepreneurship. He attended Huadong Normal University in Shanghai, where he studied management. He said he began investing in stocks in 1998, even before he graduated.
He worked for several years as a university administrator, then became a full-time investor and eventually started a company to manage investment funds. He now manages two private equity funds, both named after him: Caiyuan No. 1 and Caiyuan No. 2.
"I think Wenzhou people are very persistent," Mr Xu said.
"They can endure hardship. They don't surrender to failure."