Sorry if it's a basic question.
Suppose corporation ABC went through public offering many years ago. ABC retained 30% of the shares, and 70% are being traded. The very initial offering, ABC made money. But thereafter, all the share trading and the associated money doesn't go to ABC, rather between the share holders.
How does a drop in share price due to trader fears (or an action ABC took) affect ABC itself? According to How can a company run out of cash when its stock prices is dropping? it does not affect the corporation.
Stocks usually don't affect the immediate operation of a company, since they are traded on secondary markets (stock exchanges) among stock owners.
So how does it affect the overall economy?