Many people consider bitcoin as an investment, they buy bitcoin at low price and they want the price to get high so that when they sell it, they will earn profit. Too, if bitcoin price is high, bitcoin will have a huge purchasing power thus people who has bitcoin will able to buy many things from it.
Mostly if will not denied the fact, they or we buy and hold bitcoin because we are believing that the value will rise and will bring us a good profits in returned, holding bitcoin and pushing more investors and businesses to adopt and start also a journey to this system will make bitcoin as a huge investment and believing on it will be a fortune for many.