A stock price reflects a company's valuation. And it is affected
by its specific factors as well as the overall economic, and
political condition, where that stock is in.
Therefore a stock price is affected by the price of oil, inflation
rate, GDP growth, average earnings growth, central bank interest
rate, etc, as these are indicative of the overall economy.
How closely a specific stock follow the general move of the broader
market as affected by these factors, depends on the nature of each
company. Some companies are more sensitive, while others are less
sensitive. This difference could be caused by its size, or its
sector(s) where it's in.
If you want to interpret the datas..... = means same move, ><
means opposite.
GDP growth =
Inflation rate ><
Central bank interest rate ><
Average earnings growth =
Oil price ><
Some more minor datas:
Unemployment ><
Consumer spending =
Housing data =
Etc...
Example, up in GDP growth, means better overall economic
conditions, the stock market goes up as well. Up in inflation rate,
means worse overall economic conditions, the stock market goes down
(opposite).
When all these datas come up, you are confused how to interpret
them as a whole. Like if it's 3 up, 3 down, so what does that
mean?
Even the best economists miss their forecasts. We don't try to be
an economist. We look at the overall market price. The overall
market price has already priced in everything it knows including
the overall economic and political conditions.
So like I said, we just be a free rider. Just look at the
INDEX.
The index reflects the overall market price, which means it
reflects the market digestion of overall economic and political
condition as a whole.
Since a specific stock is always affected by its specific factors
as well as general economic and political factors, the index will
always affect a specific stock price. How much so, look at the Beta
(correlation of the 2). If you want to break it down, like oil
price, also find the Beta for that component.
Your second question. If people sell, price drop of course. If it
drops from $1 to $0.10 like you said, you don't need to pay for any
maintenance and it's safe, but theoretically you got a massive
loss. This should worry you more than any maintenance. Such massive
lost will not happen in real life though, since you have risk
management like placing stop-loss.
Your third question. You can spread rumours of course and if the
stock is cheap and small, your rumour can move the stock, and you
can con them all. However if the stock is big, your rumour will
have very little impact.