When should we think about client-side caching for real-time updates

We're working on a dashboard that needs to show data that updates a lot, almost instantly. We've looked into server-side caching and pub/sub systems. But, I'm curious about the pros and cons of adding client-side caching to that. Are there times when it's actually a good idea to cache data right in the browser or a mobile app so it shows up faster? Even if that means we have to deal with keeping the cache up-to-date on the user's end? What have you all found works best?