Okay… Stupid question of the day…

With the tapered pistons, does the piston go in with the taper up or down? I was thinking that it goes in with the taper facing up because that make sense in my mind.. But this past weekend I built my 1/8th buggy and it came with tapers… Told me that they face down?? So now I’m confused… Can someone tell me what is correct and why?
Thanks!!