Diversification vs. Concentration.

Your portfolio can be likened to a college application.

If you diversify your portfolio safely, it’s like having a well-rounded resume. You are going to get in somewhere decent, and you will most likely be happy and secure.

On the other hand, having a concentrated portfolio is like having a very specialized resume. You are not going to qualify for many places, simply due to what you do being so specific, but you only need one really great university to accept you for your niche to skyrocket.