The Quanticed blog
The maths behind the money
Long-form, carefully argued pieces on investing, borrowing, and personal finance — taking a closer, more numerate look at the things everyone thinks they already know.
The Minimum-Payment Trap: How a Small Balance Becomes Decades of Debt
A $5,000 balance and a card that 'only' asks for $100 this month feels manageable. Pay just that minimum, though, and the same balance can take well over a decade to clear and cost more in interest than you ever spent.
June 26, 2026 · 9 min read
Lump Sum vs Dollar-Cost Averaging: What the Maths Actually Says
Everyone says drip-feeding a windfall is the smart, cautious move. The maths disagrees: lump-sum investing wins roughly two times in three. But DCA isn’t about return — it’s about regret. Here’s how to tell which one is for you.
June 26, 2026 · 9 min read
Same Average Return, Opposite Outcomes — the Retirement Risk No One Warns You About
While you're saving, the order of your returns doesn't matter — only the total does. The moment you start withdrawing, order becomes everything. Two retirees, identical returns in reverse, opposite fates.
June 26, 2026 · 10 min read
The Real Value of a Lottery Ticket: The Expected-Value Maths Behind the Jackpot
When the jackpot hits half a billion, it feels almost rude not to buy a ticket. But what is that ticket actually worth? The expected-value maths gives a precise, and reliably negative, answer.
June 26, 2026 · 9 min read
Right on Direction, Wrong on Money — Why Your Call Can Lose When the Stock Goes Up
The stock moved exactly the way you predicted, and your call option still lost money. It isn't a glitch. Direction is only one of four things a long call needs to get right. Here's the maths.
June 26, 2026 · 10 min read
Average Returns Lie: Why the Number Your Fund Reports Isn’t What You Earned
A fund that “averages 9% a year” almost never turns $10,000 into what 9% compounding would suggest. The gap isn’t fees or bad luck — it’s arithmetic. Meet the geometric mean and volatility drag.
June 25, 2026 · 10 min read
Why Leverage Can Turn a Mediocre Rental Into a Great Investment — or a Disaster
The same rental can show a steady 7% cap rate and a thrilling 13% cash-on-cash return — or a terrifying negative one. The difference is the mortgage. Here's how leverage really works.
June 25, 2026 · 9 min read
Marginal vs Effective Tax Rate: Why a Raise Never Pushes Your Whole Income Into a Higher Bracket
“A raise will bump me into the next bracket and I'll take home less.” It's one of the most common money myths — and it's simply wrong. Here's what brackets really do to your paycheck.
June 25, 2026 · 8 min read
Paying Off Your Mortgage Early Isn’t Always the Smart Move
“Debt is bad, so clear the mortgage as fast as you can” feels like obvious good sense. The honest answer is: it depends — on your rate, your taxes, your liquidity, and how much a paid-off home is worth to your peace of mind.
June 25, 2026 · 11 min read
Renting Isn't Throwing Money Away
“You're just paying your landlord's mortgage.” Maybe — but a chunk of a mortgage payment is just as unrecoverable, and the down payment has an opportunity cost. When buying really wins is a numbers question.
June 25, 2026 · 9 min read
The 15.3% Surprise: How Self-Employment Tax Really Works
Your first year self-employed, an extra 15.3% tax lands that you never noticed as an employee. It isn't a penalty — it's the half your employer used to quietly pay. Here's how it works.
June 25, 2026 · 8 min read
Your Tax Refund Isn’t a Bonus — It’s a Bill You Overpaid
That refund cheque feels like free money. It isn’t — it’s your own money, handed back without interest after you overpaid all year. Here’s what the “windfall” actually costs you, and how to stop giving it away.
June 25, 2026 · 9 min read
Why Most Active Funds Lose — and It’s Arithmetic, Not Bad Luck
It’s tempting to think well-paid experts should beat a “dumb” index. But the average active fund must underperform — not usually, not on the evidence, but by arithmetic. Here’s the proof, and what to do about it.
June 25, 2026 · 10 min read
Your Bonus Isn't Taxed at 40% — It's Withheld That Way
You got a $10,000 bonus and barely $6,500 landed in your account. It feels like punitive taxation. It isn't — it's withholding, and it isn't the final word.
June 25, 2026 · 7 min read