Why is it more secure?
SMS and email codes can be intercepted, forwarded, or phished — an attacker who has your password and your phone number may still be able to get in. Sign-in Approval works differently: the approval happens inside the Questrade app itself, and the notification goes only to your Primary Trusted Device. Even if an attacker has your credentials, they cannot approve the login without physical access to your Primary Trusted Device (e.g., your phone).