For market with an atomless continuum of assets, we formulate the intuitive idea of a well-diversified portfolio, and present a notion of exact arbitrage, strictly weaker than the more conventional notion of asymptotic arbitrage, and necessary and sufficient for the validity of an APT pricing...

We first report that one-minute returns on TOPIX have exhibited significant autocorrelation at five-minute intervals since 1997/98, which implies there is an arbitrage opportunity. Special quotes that are issued whenever there is a price jump in excess of a predetermined band seem to be the...

Let S=(S_t), t=0,1,...,T (T being finite), be an adapted R^d-valued process. Each component process of S might be interpreted as the price process of a certain security. A trading strategy H=(H_t), t= 1,...,T, is a predictable R^d-valued process. A strategy H is called extreme if it represents a...

At arbitrary prices of commodities and assets, fix-price equilibria exist under weak assumptions: endowments need not satisfy an interiority condition, utility functions need only satisfy a very weak monotonicity requirement, and the asset return matrix allows for redundant assets. Prices of...

This paper investigates the limit properties of mean-variance (mv) and arbitrage pricing (ap) trading strategies using a general dynamic factor model, as the number of assets diverge to infinity. It extends the results obtained in the literature for the exact pricing case to two other cases of...