Why only long term investments? What do they care if I buy and sell
shares in a company in the same year?
Simple, your actually investing when you hold it for a long term. If you hold a stock for a week or a month there is very little that can happen to change the price, in a perfect market the value of a company should stay the same from yesterday to today so long as there is no news(a perfect market cannot exist).
When you hold a stock for a long term you really are investing in the company and saying "this company will grow". Short term investing is mostly speculation and speculation causes securities to be incorrectly valued. So when a retail investor puts money into something like Facebook for example they can easily be burned by speculation whether its to the upside or downside.
If the goal is to get me to invest my money, then why not give apply
capital gains tax to my savings account at my local bank? Or a CD
I believe your gains on these accounts are taxed... Not sure at what rate.
If the goal is to help the overall health of business, how does it do
that? During an IPO, the business certainly raises money, but after
that I'm just buying and selling shares with other private
shareholders. Why does the government give me an incentive to do this
(and then hold onto it for at least a year)?
There are many reasons why a company cares about its market price:
A companies market cap is calculated by price * shares outstanding. A
market cap is basically what the market is saying your company is
A company can offer more shares or sell shares they currently hold in
order to raise even more capital.
A company can offer shares instead of cash when buying out another
company. It can pay for many things with shares.
Many executives and top level employees are payed with stock options,
so they defiantly want to see there price higher.
these are some basic reasons but there are more and they can be more complex.