PT - JOURNAL ARTICLE AU - Martin S. Fridson AU - Jón G. Jónsson TI - Instrumentality AID - 10.3905/jpm.1995.409543 DP - 1995 Oct 31 TA - The Journal of Portfolio Management PG - 9--20 VI - 22 IP - 1 4099 - https://pm-research.com/content/22/1/9.short 4100 - https://pm-research.com/content/22/1/9.full