Dear all

I have a technical doubt in the following facts.Especially pricing a forward and future on a tradable underlying we do everything wrt a risk neutral measure.But if the underlying becomes non-tradable then I have seen people switching over everything to a forward measure where the Numeraire is given by a zero coupon bond.The logic behind this is I guess in the first case when the underlying is tradable we can set up a replication strategy with the underlying and money market account(numeraire in risk neutral measure ) while giving no arbitrage arguements for both forwards and futures.But if the underlying is not tradable we shift to the forward measure to construct a replication strategy using the numeraire(a zero coupon bond ) and money market account. Please correct me if I 'm wrong .

thanks.