One of my favorite quotes about startups/VC, from legendary VC Mike Moritz of Sequoia:
I rarely think about big themes. This business is like bird spotting. I don’t try to pick out the flock. Each one is different and I try to find an interestingly complected bird in a flock rather than try to make an observation about an entire flock. For that reason, while other firms may avoid companies because they perceive a certain investment sector as being overplayed or already mature, Sequoia is careful not to redline neighborhoods.
In traditional business thinking, generalizations about “flocks” i.e. markets/categories/sectors can be very useful. But when your job is to identify exceptions, generalizations can be dangerous.