Dozens of Hong Kong investors in failed Lehman Brothers—backed derivatives who were left out of a recent settlement protested on Sunday outside the headquarters of the territory’s central bank.

About 37,000 investors who bought more than 15.5 billion Hong Kong dollars ($2 billion) of Lehman—related financial products saw their investments cast into doubt after the U.S. investment bank collapsed last September. Angry investors said the banks who sold the products misled them about the risk.

Hong Kong regulators announced a settlement last month that requires the banks to return up to 70 percent of the principal to thousands of investors. But the deal excluded “experienced” investors over the past three years.

These “experienced” investors protested on Sunday, clutching signs that said “I am not experienced” and demanding that they be included, footage from Hong Kong’s Cable TV showed. The report said many of the nearly 100 demonstrators were elderly.

Critics have questioned the “experienced investor” classification, saying it would include elderly investors who blindly trusted bank sales staff.

Calls to Hong Kong’s central bank, the Hong Kong Monetary Authority, and the Chinese territory’s Securities and Futures Commission went unanswered.

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