Flex or price flex refers to changes in the spread or margin on a syndicated loan made when demand varies from what had been anticipated. Upward flex is an increase in the spread relative to LIBOR, or other market interest rate, which is made when the loan margin is too low to clear the market. Reverse flex is the opposite, a decrease in the spread which occurs when the loan is oversubscribed and the market clearing spread is lower than the original one.