Ptolemy, Galileo, and Financial Markets

Assume nothing, new models and analytical tools, coupled with constant revision, questioning everything, reassessing, and re-analyzing, are essential to success in today’s markets. Often, and we are seeing that in today’s market, relying on bad assumptions, dogma, or prior belief can be disastrous.

This story about medieval astronomy applies directly to investment strategies, market valuations, and portfolio construction today. It’s the same lesson –begin by questioning the very assumptions on which an entire system is built. There is also a very specific application of this model that is particularly current.

One of the most valuable lessons is to assume no knowledge and analyze closely every initial assumption. Nothing is so obvious that it can’t be questioned. Unexamined ideas and assumptions will eventually be useless. Any assumptions and any model used to explain and predict anything (whether it’s the movement of planets or financial markets) needs to go back to first principles and discard any assumptions, preconceived knowledge, or bias.