B) capital gains
The stock market is based on "expectations". If more people think a company's prospects are improving, "all things being equal", the stock price should go up.
However, "all things being equal" probably never happens. During the Great Depression, while many companies went bankrupt, other companies prospered and positioned themselves for the rebound, even though their stock price fell dramatically.
Figuring out the stock market is like figuring out women. Easy to say, hard to do.
More buyers then sellers. Increase is stock value (A)
Banks and War
A) market share
B) capital gains