In 1987, Lo derived an upper bound on the price of a European call opt
ion on a single asset. Lo's bound depends only on the mean and varianc
e of the terminal asset price and is termed a semi-parametric bound. T
his paper derives similar semi-parametric bounds on a European call on
the maximum of any number of assets. A distribution-free bound for th
e price of this option is obtained. The bound depends only on the mean
s and covariance matrix of the returns on n underlying assets. The bou
nd is obtained by optimizing over the entries of a positive definite m
atrix A. This can be accomplished by a technique known as semidefinite
programming. We demonstrate the methodology using two specific applic
ations. The first concerns the valuation of a European call option on
the maximum of several assets. This is known as an outperformance opti
on and is of some practical interest. The second application concerns
the valuation of a discretely adjusted lookback option. These lookback
options are of interest in connection with certain equity annuity ins
urance products.