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📅 March 2026·MarketMVP Educational Guide

WALL STREET × GAME DAY

What is Compound Interest? The 8th Wonder of the World Explained

What is compound interest? Compound interest means earning returns on your returns, not just on your original investment. £1,000 earning 10% annually becomes £1,100 after year one. In year two, you earn 10% on £1,100 — not just the original £1,000. Over decades, this compounding creates exponential growth that massively outpaces simple returns.

THE SNOWBALL DOWN THE MOUNTAIN

Compound growth is like rolling a snowball down a slope. At the top, it's small and moves slowly. Halfway down, it has accumulated enough mass to pick up more snow with every rotation. By the bottom, what started as a handful of snow is an enormous ball. The further it travels, the faster it grows — but the critical factor is starting early enough to have distance to travel.

THE NUMBERS THAT MAKE IT REAL

START AGEMONTHLY INVESTMENTRATEVALUE AT 65
22£2008%~£870,000
32£2008%~£380,000
42£2008%~£155,000
22 (double)£4008%~£1,740,000

Starting at 22 vs 32 with the same investment produces more than double the outcome. 10 years of additional compounding is worth more than doubling the monthly contribution.

HOW COMPOUND INTEREST APPLIES TO STOCKS

Stocks compound in two ways: share price appreciation (your investment grows as the business grows) and dividend reinvestment (cash dividends buy more shares, which earn more dividends, which buy more shares). The most powerful long-term stock portfolios combine both.

FREQUENTLY ASKED QUESTIONS

What is the Rule of 72?
The Rule of 72 is a shortcut for estimating how long it takes for money to double. Divide 72 by the annual return rate. At 8% annual return, money doubles every 9 years (72 ÷ 8 = 9). At 10%, it doubles every 7.2 years. At 6%, every 12 years. This simple rule shows why small differences in annual return have dramatic long-term effects.
Is compound interest the same for stocks and savings accounts?
The principle is the same but the rates differ dramatically. A savings account in 2026 pays approximately 4-5% (varies with rates). The S&P 500 has historically averaged approximately 10% annually. At 5% vs 10%, £10,000 over 30 years becomes £43,000 vs £175,000 — a fourfold difference from the rate alone, compounding amplifies this significantly.
How do dividends create compound growth?
When dividends are automatically reinvested (DRIP programmes), each payment buys more shares, which earn future dividends, which buy more shares. This creates compounding specifically within dividend-paying stocks. Coca-Cola (KO), which has raised its dividend for 62 consecutive years, is a classic example of compounding through dividend growth.

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Educational purposes only. MarketMVP OVR scores, tiers, and athlete comparisons are proprietary educational tools — not financial advice, investment ratings, or recommendations to buy or sell any security. Always conduct your own research. Full disclaimer