Japan Exchange Group Inc., the operator of the largest stock exchange outside the U.S. by value, needs to attract more female investors, according to a report released Wednesday based on a survey of 10,000 people.

Men outnumber women by about 2-to-1 among people claiming to have knowledge about equities, according to the results of the survey conducted by NTT Data Institute of Management Consulting Inc. on behalf of the Tokyo Stock Exchange.

Female respondents said they don't invest because the risks look very high, they don't feel they have the knowledge and they believe investing is speculative or only for rich people, the survey, commissioned in March, showed.