Five years after risky mortgage-backed securitization products helped set off the worst financial crisis since the Great Depression, eight in 10 U.S. retail investors still cannot recognize one in trade disclosures, according to a Securities and Exchange Commission study.

Mandated under the Dodd-Frank Act, the SEC designed an online survey to test investor respondents about different trades made on Wall Street and what different disclosures tell about them.

Only 17% of those surveyed correctly identified a mortgage-backed security in a trade confirmation given to them with multiple-choice answers.

But 53% of the respondents were able to recognize a stock trade. And nearly 58% correctly identified a trade confirmation as involving a mutual fund, according to the results.

"Online survey respondents generally reported having some level of understanding of the disclosure documents provided to them in the survey," the SEC said in its study. "However, many of the online survey respondents failed to correctly answer some of the comprehension questions related to the disclosure items they reviewed."

There was also a disconnect between what the retail investor thought he or she was reading in the trade confirmations when it came to what the financial institution involved in the deal was making.

When given an MBS trade, roughly 24% of respondents correctly recognized that the information provided in the trade gave no information about what the financial intermediary was compensated in the deal.

"From methods to improve disclosures to best practices for investor education programs, the study addresses a wide range of areas related to investor literacy," said Lori Schock, director of the SEC office of investor education and advocacy. "It is a 'must read' for any individual or organization dedicated to educating investors."