Disclosure: this post was written with the assistance of an AI system (Claude), which wrote the analysis code, ran the experiments and drafted the text. The topic, the constraints, the data choices and the final review are the author’s. Under Korea’s jeonse system a tenant hands the landlord a lump sum worth half to four fifths of the home, pays no monthly rent for two years, and receives it back at the end....
Disclosure: this post was written with the assistance of an AI system (Claude), which wrote the analysis code, ran the experiments and drafted the text. The topic, the constraints, the data choices and the final review are the author’s. The ten largest S&P 500 companies are around 41% of the index against roughly 19% in 1990, and the usual conclusion is that index investors are no longer diversified. There is a formula for that....
Disclosure: this post was written with the assistance of an AI system (Claude), which wrote the analysis code, ran the experiments and drafted the text. The topic, the constraints, the data choices and the final review are the author’s. On 31 July 2026 the KOSPI rose 17.91% in a single session, the largest one-day gain in its history, days after a circuit breaker halted trading and inside the second-worst month the index has ever had....