But when trading ended Wednesday it was still a mystery to many why stocks had rallied so sharply.
Futures and options trading will also end early, with the latest finishing about 2:30 P.M.
Gold prices rose in domestic activity after trading ended mixed overseas.
Developments are often announced after trading has ended for the week.
Apple shares closed up 87.5 cents, at $48.125, when trading ended on Friday.
The announcement of the spinoff came after trading had ended, with Alco closing down $1.625 at $58.375.
Open-outcry trading of financial options ended in May.
In Tokyo, where trading ended before the figures were released, the dollar fell 2.02 yen, to 124.13.
But when trading ended, the dollar had not quite reached the levels that traders said would signal a new stability.
The proposed spinoff was announced after trading had ended.