“Both proceedings have garnered some eccentric reactions, including claims that the S.F.C. is seeking to chill independent research into mainland companies,” Mark Steward, then executive director of enforcement at the securities and futures commission, said in March 2015, in rare public remarks on the Moody’s and Citron cases.

“There should be no chill in respect of reports that are soundly and reasonably prepared,” said Mr. Steward, who now heads enforcement at the Financial Conduct Authority in Britain. “At the same time, the investing public needs protection from the cynical use of false or misleading publications that drive down share prices for the wrong reasons, and there should be accountability for shoddy research especially when it affects stability in our markets.”

The securities appeals tribunal, in its ruling on the Moody’s case, acknowledged the right of financial market participants to freedom of expression.

“The freedom, however, is not absolute,” the tribunal said at the time, citing the Hong Kong Bill of Rights. “The exercise of the freedom carries with it ‘special duties and responsibilities’ and may therefore be ‘subject to certain restrictions.’ ” It ruled that, in the Moody’s case, the ratings agency’s criticism of the financial health of Chinese companies had overstepped those restrictions.

Mr. Left of Citron was found guilty by the tribunal in August. In the sentencing, Hong Kong’s Market Misconduct Tribunal issued the maximum possible trading suspension against him, it said in a statement on Thursday. The punishment was for what the regulator had said was “false and misleading information” about Evergrande in a report that Citron published in June 2012.

Those allegations, denied repeatedly by Evergrande, included claims that the developer was “insolvent and had consistently presented fraudulent information to the investing public.”

China’s property market has recently rebounded from a slump, and prices have soared to the point that analysts have warned of a bubble.

But as recently as last year, many developers, including Evergrande, which has been one of China’s most indebted real estate companies, were still struggling financially after years of lackluster property sales. In March 2015, Evergrande sought a $16 billion lifeline from state-controlled banks.