Robert McLister·General·April 18, 2010Prime Rate A reference interest rate used as a basis for quoting other lending rates, like those of variable-rate mortgages and lines of credit. Prime rate used to be the rate at which financial institutions lent to their best customers. This is no longer necessarily the case. A historical view of prime rate can be seen here. Like news like this?Join our CMT Updates list and get the latest news as it happens. Unsubscribe anytime. SUBSCRIBE! Thank you for subscribing. One more step: Please confirm your subscription via the email sent to you.