Do I have to pay income tax on the appreciation in value of assets at the end of each year? What about exchange rate variation?

No. As was done in the previous tax regime, only gains determined on the effective sale, liquidation, redemption, or maturity of assets will be taxed. There will be no taxation as long as it is a mere appreciation (potential gain).

The same reasoning applies to exchange rate variations, which will be determined and taxed only upon the effective sale, liquidation, redemption, or maturity of the asset.