Herfindahl Hirschman Index (HHI)

• The Herfindahl–Hirschman Index (HHI) is a widely used single-number measure of market concentration. – HHI = sum of the squared market-share percentages of…

Herd Instinct

Herd instinct (or herd mentality/herding) is the tendency for people to mimic the actions of a larger group—often without independent analysis—because they assume others…

Hedge

A hedge is an investment or trade taken to reduce the risk of adverse price movements in an existing position. It functions like an…

hedge fund

• A hedge fund is a privately offered, actively managed investment vehicle that pools capital from accredited investors (institutions and high‑net‑worth individuals) and pursues…

Health Savings Account (HSA)

An HSA is a tax-advantaged savings and investment account you can use to pay for qualified medical expenses. HSAs are available only to people…

Health Reimbursement Arrangements (HRAs)

Introduction A Health Reimbursement Arrangement (HRA) is an employer-established benefit that reimburses employees for qualified medical expenses and, in some HRA types, for individual…

Health Maintenance Organization (HMO)

An HMO is a type of managed‑care health insurance that gives members access to medical services through a defined network of doctors, hospitals and…

Health Insurance

A practical, step‑by‑step guide to understanding health insurance, comparing plans, and lowering your out‑of‑pocket risk. Sources: Investopedia — “Health Insurance” (provided by you) and…

Hawala

Introduction Hawala is an ancient, informal system for transferring value that originated in South Asia (around the 8th century) and is still used worldwide.…

Harry Markowitz and Modern Portfolio Theory

Key takeaways – Harry Markowitz (b. 1927, d. 2023) developed Modern Portfolio Theory (MPT), which reframed investing from evaluating individual securities to optimizing entire…