My banking site has an extremely short timeout, like 5 minutes but feels like less, which is really burdensome when you're looking at stock data while trying to

My banking site has an extremely short timeout, like 5 minutes but feels like less, which is really burdensome when you're looking at stock data while trying to read news about it. So I had to create a Tapermonkey script which reloads only a specific page of the bank every 30 seconds and I move that tab somewhere where it doesn't disturb me. How is any of this improving security?