Catch a falling knife?
AKA "don't fight the tape" or "the trend is your friend". The idea that it's just not reasonable to expect an ongoing price movement to suddently reverse course just because today we bought in. OK, so it does happen once in a while, but in my experiance it's not often enough to cover losses.
Except that you never know where the bottom is. But if something was a good buy at X dollars, it is a better buy at 3/4 X or 1/2 X, every time.
And nothing, I mean nothing, will take the place of hydrocarbon energy in our lifetimes. So a prediction that energy, and the companies that produce it, will be here for quite a while longer.