Buy&Hold is adept at solving tax issues.
Buy&Hold is adapted to solving tax issues.
Both sentences are gramatically correct but have different meanings.
The adjective "adept" means skilled, competent, professional, versed, dab hand, wizard, expert, skillful, proficient.
It doesn't mean "adaptado" nem "adepto". The word "adepto" in Portuguese most often translates as supporter, follower.
The word "adaptado" could translate as used to, suitable, adjusted, etc. depending on context.
As always, for vocabulary choice, context is king.
When studying, avoid learning new words in isolation, they are wild beasts and their meaning is only constrained by the sentence and wider textual area environment. Also, it's useful to add the preposition the new words require when taking notes. They too may alter the meaning.