I don’t understand why (non-dividend paying) stocks increase in price when a company is successful; is it just because everyone expects that everyone else will find it more valuable because the company is doing better? Is the link between this type of stock and the company really just phycological? If investors are getting something other than dividends or just “ownership,” from buying this type of stock, what is it?

I don’t understand why (non-dividend paying) stocks increase in price when a company is successful; is it just because everyone expects that everyone else will find it more valuable because the company is doing better? Is the link between this type of stock and the company really just psychological? If investors are getting something other than dividends or just “ownership,” from buying this type of stock, what is it?