The main ways that the Norwegian fund is seeking to limit its trading costs is by trading “smarter” — timing and sizing its purchases and sales better to minimize transaction costs and the impact it can have on the market — and by simply trading less, identifying when it might be better to wait or swap securities between in-house investing teams. If big investors are able to make meaningful savings on their trading costs it could crimp the earnings of Wall Street banks and trading firms that act as intermediaries.