Conjoined twins. What were called Siamese twins, in a less enlightened era. Danny DeVito+Arnold Schwarzenneggar. Two people who share some part of their bodies. Connected at the forehead, or by a thick clump of skin at the hips. Or two heads, two torsos, two legs, one butt.
Paired shares are the stock market equivalent of this concept. Two companies, two stocks, combined as one unit. Moreover, the companies have a combined management and board structure (so...conjoined twins who share a brain).
