I don't follow. Say a startup comes along and I think the entire idea, space, and sector is doomed to failure. The whole market is a no-go. I can't get rich o

I don't follow. Say a startup comes along and I think the entire idea, space, and sector is doomed to failure. The whole market is a no-go. I can't get rich off the ones I decide will be failures, and it's possible for an entire sector to fail together in a correlated way. Say, Gmail crushes all web-based email startups, or iPhone crushes all startups based on the available 2007-era mobile platforms. At least in financial derivatives trading, there is a somewhat zero-sum aspect to who is winning and losing money. Every dismal derivatives trade should have some winners on the other side.