PT - JOURNAL ARTICLE AU - Michael D. Carpenter AU - David E. Upton TI - Trading Volume and Beta Stability AID - 10.3905/jpm.1981.408797 DP - 1981 Jan 31 TA - The Journal of Portfolio Management PG - 60--64 VI - 7 IP - 2 4099 - https://pm-research.com/content/7/2/60.short 4100 - https://pm-research.com/content/7/2/60.full