Thanks for the clarification.
Diversification has and is widely accepted. We've embedded cliche's and metaphor's in our language and teachings to reinforce this belief. (e.g. don't put all you're eggs in one basket.)
Our ancestors used diversification as a means of survival when the lack of food shelter or weapons was certain death. It's instinctive, we're hardwired to believe this.
My experience is this: Diversification is a good thing; in moderation. overdiversity isn't necessarily a bad thing(although it can be in certain market conditions) but it almost always results in mundane returns.
When markets correct, it's generally broad based, your holdings may be affected.
When markets crash/melt down, very few are spared it's effects.
Certain instruments,however, don't know what the market is doing, they merely follow their own course.
So I've just contradicted myself and have actually told you nothing.
I suspect you have the right idea, own a small basket of stocks that are in your field of expertise and watch them carefully with stops.
But how do you know your correct?
Experience and hard work, followed by more hard work that yields an even great depth of wisdom and experience.
Oh...and one truly never masters it all, you never stop learning what the market is telling you.
Choose your stops wisely.
