Electrons near the top of the valence band have a negative effective mass, their energy decreases as $k$ increases from 0, and they have a positive group velocity for $k>0$.

Electrons near the top of the valence band have a negative effective mass, their energy decreases as $k$ increases from 0, and they have a negative group velocity for $k>0$.

### Subquestion 2

Holes near the top of the valence band have a positive effective mass, their energy increases as $k$ increases from 0, and they have a positive group velocity for $k>0$.

Holes near the top of the valence band have a positive effective mass, their energy increases as $k$ increases from 0, and they have a negative group velocity for $k>0$.