As someone who's tried starting a new HN for business news (forlue.com, now defunct) after New Mogul left us I found the most difficult thing was getting a niche community to consistently submit stories.

If you know of a small group of people (ideally in the financial/money industry) who'd be interested in this, get them to use it amongst each other to trade stories during the day.

I still believe there's a market for this. It just needs to start in the hands of small group of people who'll constantly use it throughout the day to communicate with each other about business-related stories.

If you get people to consistently submit good stories, readers will follow, and then some time after, albeit slowly, commenters.