
IS OWNERSHIP STRUCTURE ENDOGENOUS? 241
The median amount of institutional ownership among such firms is 63.4%.
Inasmuch as insider holdings tend to be relatively large when institutional hold-
ings are relatively small, and vice versa, the percentage of closely held shares, or
insider plus institutional holdings, has a mean of 66.2% and a median of 67.3%.
This implies that 32.7% of a typical S&P 500 company’s common stock is widely
dispersed among the general public.
Notice how the share of insider and institutional share ownership tends to
vary according to firm size, even among corporate behemoths. Among true cor-
porate giants such as GE, Exxon, Citigroup, ...