First of all, the joint-stock company, including the non-listed joint-stock company, are originated from the demand for partnership to make money, many people put money together to do business, of course, to say in advance that you accounted for a few shares, I accounted for a few shares, and made a profit when the share of the good according to the proportion of the share, the so-called share of the profit, that is, share of the dividend.
Secondly, the joint-stock company is not the money earned each year to shareholders, because it needs to use the money earned additional investment in order to expand the scale of earning more money, but some shareholders need to take their own money back to the point of subsistence, how to do? --This is the origin of the stock exchange: because the Dutch East India Company 10 years are not dividends, all the money earned are used to build new ships, 10 years after the big dividends, so the East India Company's shareholders can only see their own company to expand but 10 years can not get back any money, so in 1609 Amsterdam set up the first stock exchange in the history of the world! So in 1609 Amsterdam set up the first stock exchange in the history of the world, shareholders who needed money could sell their shares to others at a negotiated price, and what price was negotiated would of course have a great deal to do with the development of the company. That is to say, the company's ship has become more, we all know that in the future there may be a lot of dividends, so there will be more people who want to buy and fewer people who want to sell, naturally, the share price will go up.
Again, sometimes a company needs to invest heavily to expand its business, so it may have to refinance more than once, and so it may have to reissue new shares, or even issue them in another country. Since it may be possible to refinance more than once, how much to sell each additional 1 share at when it is reissued will be determined by the current share price. If your original stock is only selling for $10 in the market, but you issue new shares at $20, who will subscribe? He might as well pay $10 in the secondary market to buy it from the original shareholders. So companies generally still want their share price to be higher, so they can use the stock market to raise money when they need to expand their business.
Another answer to the question of how supply and demand affect the price of a stock: The rules of stock trading are that buyers and sellers each make their own offers, and then the latest transaction is the so-called "current price" when there is a consensus on the price. I give an example:
For example, there are now several sell orders: 1.01 (sell one), 1.02 (sell two), 1.05 (sell three)
And there are several buy orders: 0.97 (buy three), 0.98 (buy two), 1.00 (buy one)
Since there is not any single buy order and sell order price consistency, no one deal, can not be forced to buy and sell? At this point, 1.01 is called the sell price, 1.00 is called the buy price, in fact, is the seller's minimum asking price and the buyer's maximum bid.
Then if you want to sell the person does not let a penny, a buyer is very much want to buy the price to 1.01, and then the 1.01 buy order with the lowest 1.01 sell order price consistent, so the two of them on the deal. Then the transaction price is immediately refreshed to 1.01. The so-called current stock price is the price of the most recent transaction. If the last higher price was 1.00, the price of the stock instantly rose by 1 percent.
If the 1.01 sell order has been bought out, sell one becomes 1.02, sell the person who is self-possessed want to sell less, or not let, want to buy people or more, hanging 1.01 price to buy has been unable to buy, may be someone hanging 1.02 to buy, if the transaction if the price is up again ......
Does that make sense?