Pride. Being proud can be seen as boasting.
Do's and Don'ts
DON'T perform to the interviewer.
DO be factual and understated.
DO SCRIPT: Investment Manager: [Boasting] We are the biggest, the best and the most proactive in the current market.
DON'T SCRIPT: Investment Manager: [Humble] We're doing well, our last investor survey put us fourth in the top ten so we're doing well but there's room for improvement.
Your audience will trust you and want to know more.