On the closure in the Emery topology of semimartingale wealth-process   sets
  A wealth-process set is abstractly defined to consist of nonnegative c\`{a}dl\`{a}g 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. 
Constantinos Kardaras
q-fin.PM math.PR