Individual gold ownership is specified in Article 4 Decree 24/2012/ND-CP as follows:

Responsibilities of businesses buying and selling gold jewelry and fine arts

1. Legal gold ownership rights of organizations and individuals are recognized and protected according to the provisions of law.

2. The State Bank is the agency that, on behalf of the Government, uniformly manages gold business activities according to the provisions of this Decree.

3. The state has the monopoly on producing gold bars, exporting raw gold and importing raw gold to produce gold bars.

...

Accordingly, individual ownership of gold is recognized and protected by law.

In addition, as mentioned above, the law only prohibits the act of buying and selling gold bars with businesses and credit institutions that have not been licensed to trade gold.

Article 2 Decree 24/2012/ND-CP Specifies that the subjects of application of the regulations are organizations and individuals with gold business activities in the territory of Vietnam and other agencies, organizations and individuals related to gold business activities.

Therefore, individuals who do not have gold business activities are not covered by this decree.

Buying and selling 9999 gold bars or other types of gold bars between individuals and individuals who do not have gold business activities is currently not subject to any legal regulations.

Therefore, individuals buying and selling 9999 gold bars with each other does not violate the law.