While I mostly agree with you guys about general rules, there are still some minor things that should be considered.
1. ALL really good .com names are already taken.
Regarding this, using a plural in prefix is a small price for owning still not-so-bad name.
Personally I don't think that StockInvesting and StocksInvesting
makes a huge difference.
2. Most financial search terms are in plural, eg. stocks, options, bonds, funds, etc.
3. There are so many bad names in the sector, that for some companies obtaining more appealing name would be a blessing for their internet presence, either by renaming their site or by
using new name for simple redirecting to their existing site.
I think e.g. Stocks-Advice.com would generate much more hits then NameSurnameTrading.com.
Well, those are at least my opinions. Lets see can I make something of it.