I imagine the hope is that the company keeps growing, so the share price will rise that way. Also, the company can buy-back shares to keep the number in circul

I imagine the hope is that the company keeps growing, so the share price will rise that way. Also, the company can buy-back shares to keep the number in circulation lower and to increase the stock price, or it can consolidate its shares by merging them, so each shareholder receives one new share for each two old shares. Lastly, if you're looking at stock charts, the data provider will usually adjust historical values to take into account dividends and splits, giving you an accurate view of what the price would have looked like if the number of shares issued had never changed.