Basic Shear Wall Diagram
This second example is for a wall with higher shear loading that
begins to overtake the weight of the system.

Resulting Forces
Note that as lateral loads increase, the maximum tension and
compression in the triangular force pair increases.

At the bottom diagram, adding the two resulting forces together
yields a diagram that indicates a residual tension in the system.
Providing all other criteria are met, this tension can be left
unaddressed (no hold-down).

For lateral loads (triangular force pair)...

Mot = (Vroof * H) + (Vwall * H/2)

For vertical loads (rectangular force)...

Mr = (Total Weight * L/2)

And finally...

"a" = (Mr-Mot)/(Total Weight)

max. comp. = (2/3)*(Total Weight/a)

Alternate Result
The bottom diagram can be redrawn to show a single force in place
of the triangular distribution.  This is the first step in understanding the
use of hold-downs in shear walls.