economics

the only academic economics useful for trading

September 09, 20222 min read
CompVis SD v1-4 Prospect Theory Economics cum Laude
image generated by CompVis Stable Diffusion v1-4 on 2022-09-15

Prospect Theory (for traders):

1. Gains feel less good than losses hurt

takeaway: Let winners ride, and take losses more aggressively

People tend to ride losses too long and take gains too early.

In technical speak, people are risk averse over gains (concave utility) and risk seeking over losses (convex utility).

Over time, the market keeps too much compensation for risk, while human investors take more punishment than they need to.

2. People overweight low-probability events, underweight high-probability events

takeaway: Use math to assess distributions, don't eyeball it

Our brain makes the extreme outcome seem more salient, which is an evolutionary bias towards survival.

Our gut feel is predictably biased to pay less importance to the common outcome, and to pay more attention to the extraordinary outcomes. Intuition cannot reliably make impartial weighing decisions.

Mathematics gives us tools to calculate the shape of a distribution. We can take sum-products over a discrete distribution, or we can integrate over a continuous function using calculus. The answer will be more accurate (i.e., unbiased) than the conclusions we draw using human experience.


High school economics already taught that price is determined by supply and demand. Later while on the job, I learned about more esoteric topics like Hayekian monetary theory.

In between, I paid beaucoup $$ for an Ivy League Economics degree. The only piece of academic economics I found specifically useful in my trading career is Prospect Theory, an empirical branch of Behavioral Economics.

Prospect TheoryEconomics cum laude
長話短說 (short + sweet):
Thanks for reading, anon!