re open interest & liquidity in different contracts (including XEO) <a href='read_msg.asp?message_id=20019287'>#msg-20019287</a>: <a href=http://mediaserver.thinkorswim.com/transcripts/May_31_2006_Open_Interest_and_Liquidity.pdf>Thinkorswim online Seminar: Open Interest & Liquidity</a>