Simple and clean, so works well for that niche. I would look at changing the now dated default node icons (the speech bubbles) to something specific to your niche, maybe that city skyline from your logo or a greyed out Canary Wharf (or some other financial symbol).
There also doesn't seem to be a new or recent posts option easily to hand in the forum, this is critical.
I know this sounds trivial, but first impressions and all that: Your username is too long for the restricted space you have next to posts (above the avatar) and as you'll see this a lot in posts, I would change your username and remove the .co.uk so it fits, or add a space somewhere so it splits nicely, or change the font or space there:
Other than minor stuff like this, it's a good job and you've done well.