MORT is a fairly straightforward portfolio of mortgage REITs, with an expense ratio that's lower than the other mortgage REIT-based ETF in the segment, REM. However, MORT's weaker liquidity detracts from its low-fee advantage. True to its name, MORT doesn't stray far from REITs. MORT looks a lot like our segment benchmark, including heavy concentration in the top two names. Overall, it's a great choice for exposure but access is less than perfect.