It should be expected from this paper an expansion on some distinctive issues regarding arbitrage portfolios: i) a definition on arbitrage portfolios that enables adjustments to SML and CML environments; ii) sufficient conditions to set up arbitrage portfolios against the SML and CML; iii) feasibility of separation portfolios to carry out arbitrage not only against SML but CML as well; iv) arbitrage of portfolios located in Treynor’s lines by using separation portfolios within a SML environment