Wells Fargo recommends that investors carry out a long Blackstone Mortgage (BXMT), short Apollo Commercial (ARI) pair trade. Blackstone Mortgage is trading at a 10% discount to its historic book value, while Apollo Commercial is trading roughly in-line with its historic book value ,according to the firm. If credit improves, Blackstone Mortgage's stock could rise, while Apollo Commercial is unlikely to increase significantly, according to the firm. Wells adds that Blackstone Mortgage's loan portfolio is less risky and includes fewer CMBS than that of Apollo Commercial.