Reply #5: It's a one-week extrapolation

[DavidDvorkin]

But the trend lines are a subjective choice on my part, in a sense. (I should probably add something about that to the post, so that it always shows up.)

I played around with different types of trend lines and settled on a second-order polynomial fit because it responds to recent data but doesn't overrespond. But that's all it is - it isn't revealing some kind of underlying process, the way fits to physical data may do.

If a real, long-term trend develops for one of the candidates, then the trend line will give us an idea of what will happen if that trend continues.