Limits of semistatic trading strategies
证明了离散时间下半静态交易策略的点态极限仍然是半静态策略，反驳了先前反例中关于形式不稳定的观点，指出问题出在可积性而非策略形式。
Abstract We show that pointwise limits of semistatic trading strategies in discrete time are again semistatic strategies. The analysis is carried out in full generality for a two‐period model, and under a probabilistic condition for multiperiod, multistock models. Our result contrasts with a counterexample of Acciaio, Larsson, and Schachermayer, and shows that their observation is due to a failure of integrability rather than instability of the semistatic form. Mathematically, our results relate to the decomposability of functions as studied in the context of Schrödinger bridges.