Obviously, markets are not efficient. I do not believe it is because they are such by nature but because our understanding is not deep enough. We do not use some market mechanisms that could make it efficient. There are a lot of things to understand and develop.
Presence of inefficiency means presence of opportunities. If something is mispriced then one can perform buy and sell operations, make profit and move market to a more efficient state.
We can improve our understanding of a market, find what is not right, use this and make market more efficient.
Here I present my ideas of what may be not right or not fit.
I try to explain my ideas using common language (trying to avoid “risk-neutral measures”, etc), but all of them correspond with the theory.
If you find some idea interesting, please, feel free to contact me.