Finance
Personal finance, investing, banking, markets, and financial planning
Compound Interest: The Formula, Rule of 72, and Historical Origins
Compound interest A = P(1+r/n)^(nt). Rule of 72 estimates doubling time (from 1494). Time is exponentially more powerful than rate. The constant e was discovered by Bernoulli in 1683 through studying this formula.
Compound Interest Formula and the Power of Time
Compound interest: A = P × (1 + r/n)^(n×t). Time is the biggest lever due to exponential growth. Rule of 72: divide 72 by the rate to estimate doubling time.
How Betting Odds Work: Understanding 2-to-1
At 2-to-1 odds against, a winning bet on the underdog returns 2× the wager plus the original stake. Odds reflect perceived probability — bookmakers add margin so they profit regardless of outcome.
The Dot-Com Bubble: What Happened and Why
The dot-com bubble (1995-2001): investors confused "the internet is transformative" with "every internet company will profit." NASDAQ fell 78%. Amazon/eBay/Google survived; most didn't.
High-Yield vs Regular Savings Accounts: Why People Stay with Low Yields
High-yield savings offer 4-5% vs 0.01-0.05% at traditional banks. People stay with low yields due to inertia, convenience, and lack of awareness — not because of any real disadvantage.