Brokerage statements often are inadequate for T1135-preparation purposes

Those preparing T1135 forms are finding

that the availability and quality of this information will vary greatly from one dealer to another, as well as between types of accounts. For example, very little (if any) information appears to have been provided for taxpayers using many of the popular discount brokerage accounts. Even where there is information available, you may have to double-check to ensure that the properties have been properly classified.

Neal Armstrong. Summary of Maureen Vance, "T1135 – The Saga Continues," Tax Topics, Wolters Kluwer, Number 2248, April 9, 2015, p. 1 under s. 233.3(3).