GRAM has a total supply of 5 gigagrams and doubling in 35 ye, according to its technical Whitepaper.

News     by next_big_thing

The total supply of Grams is originally limited to 5 Gigagrams (i.e., five billion Grams or 5 · 1018 nanos).

This supply will increase very slowly, as rewards to validators for mining new masterchain and shardchain blocks accumulate. These rewards would amount to approximately 20% (the exact number may be adjusted in future) of the validator’s stake per year, provided the validator diligently performs its duties, signs all blocks, never goes offline and never signs invalid blocks. In
this way, the validators will have enough profit to invest into better and faster hardware needed to process the ever growing quantity of users’ transactions.

We expect that at most 10%^36 of the total supply of Grams, on average, will be bound in validator stakes at any given moment. This will produce an inflation rate of 2% per year, and as a result, will double the total supply of Grams (to ten Gigagrams) in 35 years. Essentially, this inflation represents a payment made by all members of the community to the validators for keeping the system up and running.

On the other hand, if a validator is caught misbehaving, a part or all of its stake will be taken away as a punishment, and a larger portion of it will subsequently be “burned”, decreasing the total supply of Grams. This would lead to deflation. A smaller portion of the fine may be redistributed to the validator or the “fisherman” who committed a proof of the guilty validator’s
misbehavior.