SRL for [tacked on]: On Black Monday , Oct. 19 , 1987 , the October contract [tacked on] further gains , rising to as high as $ 491.50 for a gain of almost $ 20 on top of the Friday advances , before giving up almost $ 10 of that at the close .
ARG-M-TMP: On Black Monday , Oct. 19 , 1987 | ARG-1: the October contract | ARG-2: further gains | ARG-4: rising to as high as $ 491.50 for a gain of almost $ 20 on top of the Friday advances , before giving up almost $ 10 of that at the close