Described herein are methods to affect binding by a multivalent binding molecule to a FZD receptor and a Wnt co-receptor on a cell wherein binding by the multivalent binding molecule to both FZD receptor and co-receptor on the cell activates a Wnt signaling pathway. Also described herein are multivalent binding molecules comprising a FZD receptor binding domain and a Wnt co-receptor biding domain on either end of an Fc domain that activate a Wnt signaling pathway and methods for their use.
