PT - JOURNAL ARTICLE AU - Randall S. Billingsley AU - Don M. Chance TI - Put—call ratios and market timing effectiveness AID - 10.3905/jpm.1988.409184 DP - 1988 Oct 31 TA - The Journal of Portfolio Management PG - 25--28 VI - 15 IP - 1 4099 - https://pm-research.com/content/15/1/25.short 4100 - https://pm-research.com/content/15/1/25.full