It is correct that you tend to move into being a DBA rather than getting a job as a DBA up front.
I was restructured into being a DBA. At the time the company would have been better hiring a contractor to help for 6 months, but they were in chainsaw mode so completely missed the boat.
Having talked to a lot of DBAs most got their because the role was dumped on them or they were volunteered, very few actually asked to become a DBA. Maybe that has changed as the company i work for now, 6 people have asked me how to become a DBA. I think people look at experienced DBAs and see stability and fast dbs (I can dream ) and believe the job is easy and risk free and relatively well paid, and overlook the risks involved and all the proactive work that goes into having a well tuned system.
You know why experience counts? It was reinforced by the trainee DBA here. I have gone thru the basic day-to-day stuff and recovery scenarios and they are happy that they understand. The day i mentioned i was going on leave they became *$#! scared that they wouldn't be able to handle it, what is essentially a ultra stable database environment. Experience -> Confidence. My next step is get the trainee to do the same stuff over and over until they are familar and they are confident in their ability to perform these basic tasks.

Looking at your skills.
Scientific background
Detailed Financial market knowledge
Business owner
Web Developer

I would send your resume to the major financial companies, including brokerages, fund managers etc. Join their technical staff and if you still want to be a DBA ask the HR to organise it.
The alternative would be use all that experience and set up your own website business. Why not apply the ecology to financial markets? write a newsletter with a new technique. Have about applying ecology to a new business model?

A unrelated question: How did decimalisation kill the day trading? were u a scalper? is that the whole story???

Have Fun