Not all good things come in threes.
History shows that new companies added to the blue-chip index generally outperform. Yet there have been a few notable exceptions that led to bear markets in certain stocks.
The last time the Dow added or removed three companies simultaneously was April 2004, when American International Group, Pfizer and Verizon joined the blue-chip club simultaneously. Proving that not every recent arrival to the Dow is an instant success story, by the following year two of those three names were down by more than 25 percent.
AIG led the declines, shedding nearly 32 percent; meanwhile, Pfizer dropped 25.3 percent, while Verizon slipped 6 percent.
Since 2004, the Dow has added nine new components--and six of them were down within a year, with an average loss of 27 percent. However, Travelers and Cisco both joined the index in June 2009, and gained more than 12 percent each in their first year.
—By CNBC's Javier E. David and Giovanny Moreano.