Reflected in zero, or Reflected at zero

Question

When considering a stochastic process such as a geometric Brownian motion. Is it correct to say that it is reflected in zero? Or would it be reflected at zero?

Purely interested in what the correct wording is.

Answer 1

I have only ever seen it written or said as "reflected at zero." However, it's worth pointing out that a geometric Brownian motion has $0$ probability of hitting zero in finite time, so it's a bit of a moot point in that particular example.