Listed in the Berlin address books from 1880 to 1912. The address books describe both Moritz and his brother Max as commodity brokers (Vereid. Waaren= u. Producten=Makler) from 1880 to 1897 and as brokers (Kursmakler) from 1898 until their deaths.

An M Halberstaedter also appears in the Berlin address book for one year only in 1873 in connection with the Vereinigte Breslauer Oelfabriken= Actien= Gesellschaft; given the Silesian connection, this may be Moritz; it cannot be his brother Max as he is also listed.