Hayek's "fatal conceit" and trading

Hayek's "fatal conceit" focused on the impossibility for a socialist planner to be effective at controlling an economy. Man is not "able to shape the world around according to his wishes." The world and an economy are too complex.

For Hayek, “The curious task of economics is to demonstrate to men how little they really know about what they imagine they can design. To the naive mind that can conceive of order only as the product of deliberate arrangement, it may seem absurd that in complex conditions order, and adaptation to the unknown, can be achieved more effectively by decentralizing decisions.”

There is knowledge "which is not given to anyone in its totality" which cannot be controlled and managed. Regardless of the size of the model and the number of inputs, a planer cannot replicate the millions of interactions between economic agents in a diverse economy. 

Traders and investors will never know all the factors that may drive return during a period in time. Perhaps there will be periods when a single feature dominates returns and can be exploited, but these periods or features may not last indefinitely.

The same conceit should be avoided when trying to understand markets. Think of this as another way of saying that markets are so complex that any system or use of information cannot consistently generate profits. Markets are so difficult to understand or explain that they are beyond our control to make profits. 

Is it possible to generate profits from trading? Yes. Can those profits be sustained in the face of significant change in market structure and investor behavior? No, not without continual review and adjustment, or the accepting that any strategy can go through periods of drawdown before there is a period profitability.