🪴Investing Basics

Tuck 1000 into a piggy bank and it is still 1000 ten years later. Hand it to time instead, and it may grow to 2000 — or shrink. The heart of investing fits in one sentence: higher return always means higher risk.

Saving and investing play different roles

Saving is the tortoise: money parked in a bank account almost never loses value, but it grows slowly. Investing is the hare: assets such as stocks and funds have a chance of beating inflation over the long run, yet can lose money in any given year. The two divide the labour — money you will need within a year or two (the rent-and-groceries slice of your budget) belongs in savings; only money you can leave alone for years is a candidate for investing.

The risk-return seesaw

Line up the common asset classes on a seesaw: return on one end, risk on the other, one end always rising as the other falls.

• Bank savings: low return, almost no risk;
• Bonds: a bit more return, a bit more wobble;
• Stocks: the highest potential return over the long run, and the deepest short-term losses.

So when someone promises "guaranteed profit, 30% a year", the seesaw has already answered for you: either they are lying, or they are hiding how much risk sits behind the promise. This one rule keeps you clear of most scams. Next time a return sounds irresistible, ask: where is the risk hiding?

Don't keep all your eggs in one basket

Suppose three assets finish the year up 20%, flat, and down 10%. What should you do with 3000?

Time is compound interest's best friend

Diversification guards against betting on the wrong thing; time guards against growing too slowly. By the Rule of 72, money earning 9% a year doubles in about $72 \div 9 = 8$ years; kept up for 24 years, that is three doublings in a row — eight times the original. The early starter does not need to pick the cleverest asset; they simply bank more years of compounding.

Principal10000Annual rate 5%5Years10

Simple

15,000

Compound

16,289

Compound earns extra: +1,289

Drag the years and the rate and watch the curve lift off — unremarkable for the first decade, unstoppable in the last.

Investing can always lose, so commit only money you can afford to lose. This lesson recommends no specific product. It hands you three pieces of luggage: respect the risk-return seesaw, spread your bets, and start early. For where the compound formula comes from, watch the two curves duel in Simple & Compound Interest.

Check yourself

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Quick quiz

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1. 1. A pitch promises 'guaranteed profit, 30% a month'. What deserves the most suspicion?

   The return is too lowHigh return always comes with high riskThe entry bar is too high

2. 2. 3000 split three ways, one year later: +20%, flat, −10%. What is the net change?

   +600+100−100

3. 3. By the Rule of 72, about how long does an investment earning 9% a year take to double?

   9 years18 years8 years