TSX Market Making Program Guide Appendix B - Definitions TMX Group Page 35 Top of Book or TOB means the best price level, comprising of the best (highest) bid and best (lowest) offer in the CLOB. Total MGF means the aggregate sum of the MGF sizes contributed by all Market Makers on a security as described in the section MGF Facility. Trader ID means the trading identifier associated with an Approved Trader. TSX means Toronto Stock Exchange. TSX Rule Book means the Toronto Stock Exchange Rule Book, as such may be amended from time to time. Under Performance Month has the meaning ascribed thereto in Section 3.2.3.