The daily stressors of a career in finance can be burdensome, overwhelming, and lead to burnout on the job. To get a sense that you can handle stress safely and healthily and be able to come to work each day with a clean slate, your interviewer is looking to see that you proactively manage stress. When answering, you can certainly talk about the things you do on the job to keep as stress-free as possible, but also be sure to talk about the things you do outside of work to avoid burnout. Point out that you have the resources and ability to care for yourself and stay at the top of your game on the job.