Dang Van Thanh, chairman of Thanh Thanh Cong Group, this month sold all of his 10 million shares, or 1.54 percent stake, in sugar producer Thanh Thanh Cong – Bien Hoa Jsc.
He is thought to have netted around VND240 billion ($10.35 million).
His wife, Huynh Bich Ngoc, is the chairwoman of the sugar company, and his family still owns a combined 26.1 percent stake.
The company’s share has risen 14 percent last week.
Nguyen Duc Thuy, the founder and a major shareholder in construction firm Thaiholdings, has registered to sell his entire 24.97 percent stake made up of 87.4 million shares next month.
The company’s stock has declined by over 80 percent in May.
Founder of online entertainment group Yeah1, Nguyen Anh Nhuong Tong, has registered to sell his four million shares (12.89 percent) in the first 10 days of June.
The sale is set to be completed before Yeah1’s annual general meeting on June 15, when it will seek shareholders’ approval to issue an additional 78.6 million shares to raise capital.
YEG has fallen by nearly 35 percent this year.
The VN-Index has lost nearly 16 percent since its peak in January this year, with sharp declines seen during the last four weeks amid panic selling.
The sell-offs mean their companies are doing poorly but is unlikely to affect the market, Nguyen The Minh, director of analysis at securities brokerage Yuanta Vietnam, said.
"Many stocks are undervalued and there is no reason to sell now unless shareholders believe a stock they own is no longer attractive," he told VnExpress.