Stock prices change everyday by market forces. ... If more people want to buy a stock (demand) than sell it (supply), then the price moves up. Conversely, if more people wanted to sell a stock than buy it, there would be greater supply than demand, and the price would fall.

Do stocks ever go down?

Short selling is a speculative strategy and the downside risk of a short position is much greater than that of a long position. To summarize, yes, a stock can lose its entire value. However, depending on the investor's position, the drop to worthlessness can be either good (short positions) or bad (long positions).

Do companies lose money when stocks go down?

If the stock price falls, these investors lose money, not the company. ... When a stock price is falling, the company must sell more shares to raise money. If a stock price falls by a large amount, a company might be forced to borrow to raise money instead, which is usually more expensive.