RT Journal Article SR Electronic T1 Negatbe Betas JF The Journal of Portfolio Management FD Institutional Investor Journals SP 74 OP 76 DO 10.3905/jpm.1975.408527 VO 1 IS 3 A1 Edward A. Dyl YR 1975 UL https://pm-research.com/content/1/3/74.abstract AB