The New York Stock Exchange is all about bulls and bears, but what about horses? The NYSE will host its first live steed, along with polo star and Ralph Lauren model Nacho Figueras, on Monday to ring the closing bell in honor of the Veuve Clicquot Polo Classic. At the June 27 event on Governors Island, Britain’s Prince Harry will challenge Figueras and his Black Watch team in front of a well-heeled crowd including Julianna Margulies, Alek Wek and chef Todd English.