My speculation (and this is all speculation at the end of the day to some degree) is I also think the success of other companies impact each other, such as the recent successful SpaceX abort test. For homework one night I will run an analysis showing the rise and fall of Tesla and SpaceX stock over each other mapped to positive news. I am hypothesizing there is a correlation.
SpaceX is not publicly traded, so there’s no stock price to use for such an analysis
My company is also not publicly traded, but rest assured investors and analysts still attach a valuation to it.