This note introduces a binary version of the Kyle (1985) model, and sh
ows that there is an essential equivalence between the Kyle (1985) and
Glosten-Milgrom (1985) extensive forms. In particular, this allows th
e pricing rule in a binary version of the Kyle (1985) model to be inte
rpreted as the bid-ask quotes in a Glosten-Milgrom (1985) model.