Financial Concepts Explained
Every term behind the calculators, guides, and strategies on this site — explained plainly, the way it should have been the first time.
🔥 FIRE
The 4% Rule
The single number behind almost every FIRE calculation — and where it actually comes from.
Safe Withdrawal Rate
How much you can withdraw each year without outliving your portfolio — and why 4% isn’t the only answer.
FIRE Number
Your personal retirement target in a single calculation — and why changing the rate changes everything.
Coast FIRE
Already invested enough to retire on compound growth alone? Here’s how to know if you can stop saving and just coast.
Barista FIRE
Not fully retired, not still grinding — how part-time work covers what your portfolio doesn’t yet.
Lean FIRE
The fastest path to financial independence: a smaller target, reached by deciding to need less — not earn more.
Fat FIRE
Retiring without downgrading your lifestyle — same formula as FIRE, just a bigger number and a longer runway.
Sequence of Returns Risk
Why two retirees with identical average returns can end up in completely different places, depending on when the bad years hit.
📈 Investing
Index Funds vs. Picking Stocks
Why most professional stock pickers fail to beat a fund that just buys the market.
Expense Ratios — The Silent Fee
The one fee you’ll never see a bill for — because it’s already been taken out.
Dollar Cost Averaging
Investing the same amount on a fixed schedule — and why the market’s worst stretches are often when it helps most.
Diversification
Spreading across assets is the only free lunch in investing — here’s what the math behind it actually shows.
Asset Allocation
How you split stocks and bonds determines most of your long-run return — and most of your risk.
Rebalancing
Your portfolio drifts away from your target over time — quietly changing how much risk you’re actually carrying.
Factor Investing
The research-backed tilts — small, value, profitability — that have historically earned a premium over the broad market.
Dividend Investing
Collecting regular income without selling shares — and the trade-offs that come with chasing yield.
ETF vs. Mutual Fund
Two ways to own the same index, often one fee apart — and why that thin difference compounds over decades.
Tax Loss Harvesting
🪺 Retirement
401(k)
IRA
Roth IRA
Traditional IRA
Roth Conversion Ladder
Required Minimum Distributions
Social Security
Medicare
💰 Budgeting
50/30/20 Rule
Zero-Based Budgeting
Pay Yourself First
Savings Rate
Emergency Fund
Sinking Funds
Net Worth
High-Yield Savings Accounts
Your bank’s 0.01% savings account is quietly losing you money. Here’s the ten-minute fix.
HYSA vs. CDs
💳 Credit
Credit Score
Credit Utilisation
Hard vs Soft Inquiry
Debt Avalanche
Debt Snowball
APR vs APY
🧮 Math Concepts
Compound Interest
Rule of 72
Time Value of Money
Inflation
Real vs Nominal Returns
Net Present Value
Opportunity Cost
🏡 Real Estate
Mortgage Amortisation
PMI
LTV Ratio
Rent vs Buy
Cap Rate
House Hacking
🧾 Tax
Marginal vs Effective Tax Rate
Capital Gains Tax
Tax-Advantaged Accounts
Tax Loss Harvesting
FICA Taxes
Backdoor Roth
ACA Subsidy Cliff
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