You are right to some extent but as an investor I don't think it's necessary to think about the characteristics and factors that leads to Bitcoin up and downtrend I mean these are what traders are suppose or ment to do not investor. Investors main focus is to accumulate and hold for a long period of time so definitely there will be a downtrend but the uptrend will always supercede the downtrend within this interval of 4-10 years so you see it's not necessary to look at...
I may not understand what you mean by speculation are not just mere guesses but as much as I know, speculation are not always 100 % certain or guarantee even though much analysis is been carried out and been close isn't what we are looking for and that still sounds like a trading term. Even though no one knows when Bitcoin is going to stop existing but I believe it won't... anytime soon so why not invest and hold instead of looking or thinking of speculation that is not sure.
As a long-term investor they are not thinking about the price of bitcoin in the near future but they are thinking about how they can buy a lot of bitcoin and that is their mind. Accumulating routinely is the choice that investors focus on for the long term, they will hold until they are old.
Speculating that the price of bitcoin will definitely continue to rise because the supply is limited while the buying demand continues to increase. People want to have 1 BTC and they will start investing with the amount of money they are ready to budget for the long term until they reach 1BTC ownership. After that they will target 2 BTC and so on. That way, continue to accumulate bitcoin to be stored until we are old because bitcoin is the best investment today.