All buds have different hash (Trichromes) levels, as most people know. Obviously if you took 1g of bud and took 1g of hash made from the same bud, the hash will have more THC.

The trichromes contain most of the THC. The plant matter contains most of the Cannabinoids (CBN) which are responsible for the stoney, sleepy kind of feel of some highs.

Buds which have been used to make hash would still have some THC in though. If you tried to get it all out whilst making hash, you would get to much plant matter in the hash.