▪️real life consists of agents that manifest entirely different dynamics, whether considered as a whole or as parts (non-ergodic groups)
▪️practitioners are heuristic machines (any Italian nonna beats a Chemistry PhD in cooking pasta)
2/3 ▪️ if you consider insuring your house too expensive, you shouldn't own one in the first place
▪️Russian vernacular wisdom >>> most of financial risk managers. Готовь сани летом, а телегу зимой. (Repair your cart in December; in July your sledge remember)
▪️size matters
3/3 ▪️don't be smart, be anti-fragile (Accept only two kinds of risk, very low volatility and low upside and/or volatile and convex upside)
▪️if you work in a domain where failure is impossible (e.g. economist), you are unskilled labour
▪️If something involves ruin, probabilistic estimates are worthless. 100 people playing Russian roulette exhibit different properties from one man playing 100 times. After 7 trials, the man might face the ultimate death risk.
2/7 ▪️Only one of the potential paths will be brought into actuality. If unsure what to do next, you should ask yourself: 'Do you want this again and innumerable times again? ' Would you accept this 'eternal return' for your portfolio?
3/7 ▪️People love to make money, and hate to lose money. To survive financial storms, one must overcome this humanness. Avoid immediate gratification. Sometimes, this is more difficult than trading itself.
▪️Risk management is far more important than revenue management.
▪️Losses from a series of mediocristan risk events are highly predictable, given that they are IID (car accidents). The extremistan risks are catastrophes that cascade into even more risky events. Their aggregate losses are difficult to evaluate.
2/7 ▪️Catastrophic events violate LLN by nonlinearity and dependence, therefore losses cannot be calculated through CLT.
▪️1+a & 1-a. Perturbate your current position by +-a. If you are much better off in the +a position than the loss of -a, you are anti-fragile.
3/7 ▪️If the average of your payoffs in the 1+a and 1-a exceeds your current payoff, you are anti-fragile.
▪️antifragility is convexity.
▪️Most papers bullshit with correlation and p-value.