Guardium v2.0 (GUARD) is built to replace v1.0 (GDM). Functionally the token is identical, token counts are identical and all GUARD is to be distributed via airdrop to original GDM holders matching their current holdings.
On <Date TBD> all GDM will be deprecated in the Guardium/Guardian Circle ecosystem.
In June 2018 a vulnerability was discovered in the open-source ico-contract that the Guardium v1.0 contract was derived from.
This vulnerability permitted the incrementation of integers on known variables. Admittedly this was a serious flaw however it's not all bad. In ordered to increment a variable one had to burn their own GDM.
E.G. one could have incremented the total GDM supply count but in order to do so they must spend their own GDM in effect leaving the functional total token count in circulation lower (theoretically increasing individual token values) but leaving the overall token count returned by NEP-5 totalSupply method innacurate.
The switch to GUARD is inherently being made to ensure the value and utility of Guardium going forward. Each holder of GDM will receive an equal amount of GUARD making it a 1:1 swap with no fewer/more GUARD tokens in circulation.
In short the GUARD token is a "drop-in" replacement for GDM that will be honored in exactly the same manner as GDM was intended within the Guardium/GUARD ecosystem.
To the the best of our knowledge GDM is not yet listed on any exchanges (the token sale only concluded a month ago) and as such impact should be non-existant/minimal.
All of the wallets that support GDM are updating to support GUARD tokens going forward.