Many points have already been covered, but there's one really important one: the data.<p>It's not just about implementing a niftier interface to look at financial information. You must have the information itself first. Bloomberg has been aggregating so many different sources (hundreds, if not thousands) and they have been doing it for many years now. There aren't that many companies out there that are good at this. Only Reuters comes close to Bloomberg, as far as I know, and they aren't really that close. For individual data sources there are alternatives, but nobody else has such a comprehensive offering. There are all kinds of issues related to each data source that you would have to tackle one by one. Of course, anyone can subscribe to the different data sources, the costs are not going to be prohibitive for a well-funded startup. But regular licences would not allow you to display the data to your customers for free. You'd have to strike deals to be able to resell subscriptions to your customers and make the process easy for them. All of the data providers will want to get paid, data is not free. Once you start processing the data, you have to start archiving it because history is important. Bloomberg has been collecting data for decades. In some cases, they have data that the data providers themselves don't have because they were not so good at archiving in the past and many of them are still focused on providing real-time data only. So, if you wanted to buy historical data, it's going to be hard to get it. Often your only choice is to buy it from Reuters or Bloomberg and they are not going to give you licences for reselling the data. Note that even if you archived a lot of data from real time feeds over time, you still might have problems with the original data providers not letting you use the data for commercial purposes. And last but not least, even you got your hands on all the data that your customers would expect you to have, you still need to process it. Every data source has it's idiosyncracies that you'd have to master (not to mention that data formats have been changing over the years and documentation is often non-existing). This is very tedious and time consuming work, not the kind of stuff that excites most young startup founders. Bloomberg has been very good at processing, normalizing, and storing financial data from a multitude of heterogeneous data sources and they have decades of know-how.<p>Off the top of my head I can imagine only a couple of possible lines of attack that might have a chance:
- Start with a niche solution, then expand slowly year after year, market after market, data source by data source. Your product will have to be relatively cheap though, so that customers would be willing to buy it in addition to Bloomberg.
- Buy the data from Bloomberg. Develop your own UI. Get acquired by Bloomberg.