  For any compact Lie group $G$, we give a description of genuine $G$-spectra
in terms of the naive equivariant spectra underlying their geometric
fixedpoints. We use this to give an analogous description of cyclotomic spectra
in terms of naive $T$-spectra (where $T$ denotes the circle group),
generalizing Nikolaus--Scholze's recent work in the eventually-connective case.
We also give an explicit formula for the homotopy invariants of the cyclotomic
structure on a cyclotomic spectrum in these terms.
