They closed Tuesday with a 15% gain and took over from gaming company VNG Corp as the highest-priced share.
For the first four months Tan Cang’s XDC stock was flat at VND15,000-18,000 before it started to repeatedly hit the ceiling from April-end onwards.
By the end of June the stock, listed on the Unlisted Public Company Market, had gained the maximum daily allowed 15% on 27 days, including a straight nine-session streak.
Only 8,200 XDC shares are listed, and most of them belonging to parent company.
Tan Cang was established in 1996 by Saigon Newport Corp, a port operator based in Ho Chi Minh City, with a charter capital of VND90 billion.
Last October it auctioned over 3.2 million shares, or a 36.4% stake, but only 8,200 were bought.
Last year, its revenues fell by 15% to VND279 billion and profits by 19% to VND7.6 billion.