The financial industry does not use databases for this kind of thing much - for keeping records, and back office trade post-processing, yes, but not for market

The financial industry does not use databases for this kind of thing much - for keeping records, and back office trade post-processing, yes, but not for market data. Try wikipedia ~ Event Stream Processing, Complex Event Processing, TimesTen (now inside Oracle), Streambase... all very expensive... And if you don't need this kind of speed, then probably all of your listed databases are fine, none has a significant (x10) lead over the others. Work with what matches your skillset.