Re-recruiting for S&T / Markets

Hey guys. Did middle market IB this summer and would much rather enjoy something related to trading or market operations. When does Full Time recuriting start (or is it already underway/over?)

Are there any banks that have S&T in Chicago. CHI is my preference but would totally be fine ending up in NYC also.

Also, does anyone know of any companies in the exchange operations/ order routing / execution trader space that higher out of undergrad. At a top business school in the midwest for context.