Kardaras Constantinos, On the closure in the Emery topology of semimartingale wealth-process sets, Annals of applied probability , 23(4), 2013, pp. 1355-1376
A wealth-process set is abstractly defined to consist of nonnegative càdlàg processes containing a strictly positive semimartingale and satisfying an intuitive re-balancing property. Under the condition of absence of arbitrage of the first kind, it is established that all wealth processes are semimartingales and that the closure of the wealth-process set in the Emery topology contains all .optimal. wealth processes.