Numerous studies have shown that, on average, initial public offerings
(IPOs) are underpriced. However, while underpricing does exist on ave
rage, there is widespread cross-sectional variation across specific is
sues. Indeed, empirical results suggest that on the first day of tradi
ng, less than 70% of IPOs close above their offering price, while at l
east 25% close below the offering price.Using a sample of 2,096 IPOs o
ver the period 1975 to 1991, we show that this initial mispricing is n
ot restricted to the first day of trading. Our results provide strong
evidence of significant price trends in the shortterm aftermarket that
are in the same direction as the initial mispricing and that can last
for up to three months after the offering date. Thus, after the first
day of trading, initially underpriced IPOs continue to drift upward i
n price and earn positive returns on 17 of the first 20 days following
the first day of trading. This drift persists for approximately three
months, resulting in an additional 6.4% return above that earned at t
he offering. In contrast, prices of initially overpriced IPOs continue
to drift downward after the offering, and these IPOs earn positive re
turns on only three of the first 20 days following the offering. By th
e end of the first month of trading, these overpriced IPOs have underp
erformed matched firms of similar size by a further 4.4%, on average,
from the price at the close of the first day of trading. Following the
first three months of trading, there is little difference in the afte
rmarket performance of both groups of IPOs and, consistent with Ritter
(1991), both groups exhibit significant long-term underperformance. O
ur results have important implications for investors who obtain an ini
tial allocation of shares at the offering. Specifically, they show tha
t the initial mark-et price relative to the offering price of an IPO c
ontains important information about the short-term performance of the
stock. This in turn, suggests a profitable trading strategy. IPOs whos
e closing price on the first day of trading exceeds their offering pri
ce (that is, that are underpriced), should be held for up to three mon
ths in the aftermarket. This will yield, on average, an additional 6.4
% return above the 13.4% underpricing, resulting in a total three-mont
h return of just under 20%, on average. In contrast, IPOs that close o
n the first day of trading at a price below the offering price (that i
s, overpriced IPOs) should be sold as soon as possible in the aftermar
ket. While selling these IPOs immediately in the aftermarket cannot pr
event the average overpricing loss of 2.7%, it avoids an additional lo
ss of 4.4% if these IPOs are held until the end of the first month of
trading. There are several possible explanations for our results. Firs
t, it is possible that underpriced and overpriced IPOs have different
risk characteristics. We verify this by showing that underpriced IPOs,
on average, have higher systematic risk (beta) than overpriced IPOs o
ver the first two years in the aftermarket. Adjusting returns for thes
e risk differences, however, does not affect our results. Initially un
derpriced IPOs earn significant positive risk-adjusted returns in the
first three months following the offering, while overpriced IPOs have
negative risk-adjusted performance. Second, the underperformance of in
itially overpriced IPOs may result from underwriter stabilization acti
vities. Consistent with other studies, our results do show evidence of
stabilization activity in overpriced IPOs. We are, however, also able
to document that these IPOs continue to drift downward in price and t
hat they continue to underperform matched firms well after stabilizati
on activity has ceased. Third, the market may underreact to the inform
ation implied in the initial price of an IPO. This would be consistent
with the evidence of underreaction to the information in seasoned equ
ity offerings (Loughran and Ritter, 1995) and equity repurchases (Iken
berry, Lakonishok, and Vermaelen, 1995). Our findings concerning signi
ficant conditional trends in the short-term aftermarket for IPOs adds
to the growing body of evidence in support of price momentum or drifts
following important information events. Unlike most other studies, ho
wever, our evidence shows that the direction of these price trends can
be conditional on the direction of the information embodied in the ev
ent.