They have threatened to take action under two sections of the 1934 Securities Protection Act involving manipulative and deceptive devices. The SEC has also asked whether Ms Chen under-reported her own holdings in Trend Micro shares.
Tokyo, Japan-based Trend Micro, which is quoted on Nasdaq, would only say that it is not aware of any allegations against Ms Chen that would be attributable to the company.
Shanghai, China-based Sina Corp, also listed on Nasdaq, is an online media company, and Daniel Chiang is a former co-chairman.
