Four Stock Factors With Decades of Evidence Behind Them
One dollar bet on the US stock market's premium over cash since 1926 grew to about 770 dollars. One dollar bet on the small-stock premium over that same
MarketsData-Driven Personal Finance
Latest articles
Oct 28, 2026
The AI ETF Report Card: Eight Years of Grades, Fees Included
The ETF where an AI picks the stocks has trailed the S&P 500 by five points a year since 2017. The funds that buy AI stocks got a different grade. Both
AIOct 27, 2026
The Fulfillment Curve: Why "Rich" Is an Infinite Loop and "Enough" Is the Exit Condition
Vicki Robin solved the scope creep problem that bankrupts financial plans. The variable "Rich" is undefined. The variable "Enough" has a precise value — and it is lower than you think.
Deep diveOct 22, 2026
The Hidden Cost of a Stock Joining the S&P 500
Between the day Tesla was announced for the S&P 500 and the day it was actually added, its split-adjusted price rose about 59 percent, and the index funds
Index InvestingOct 21, 2026
The Four Channels a Rate Hike Uses to Reach Your Portfolio
The Fed raised rates in seven separate campaigns since 1980, and the S&P 500 rose across every single one. The reflex says rates up, stocks down. The
MarketsOct 20, 2026
The Upskilling Trap: Why Your Raise Might Be Making You Less Free
Getting a 30% raise feels like progress. The math shows it is regression — unless you simultaneously increase your savings rate. Here is the precise mechanism.
Deep diveOct 17, 2026
The Engineering Proof of the 4% Rule: Lyapunov Stability for Retirement Withdrawals
Treat a retirement portfolio as a control system and Lyapunov's stability theorem shows when a withdrawal rate is stable, why 4% works, and why 8% runs out of money half the time.
RetirementOct 15, 2026
Lump Sum Beats Dollar-Cost Averaging Seven Times Out of Ten
You inherit 60,000 dollars. Put it in the market today, or feed it in over a year? I tested both across 1,853 monthly windows of S&P 500 history, and
FoundationsOct 14, 2026
Emerging Markets Promised Higher Returns for Thirty Years
Emerging economies grew several times faster than the rich world for two decades. The people who bought their stocks did not collect several times the
Index InvestingOct 13, 2026
The Hedonic Treadmill: Why Spending More Never Gets You Ahead
Your brain is a homeostatic control system. Every lifestyle upgrade is a step input that the system cancels. Here is the feedback loop — and how to exit it.
Deep diveOct 8, 2026
What a Stock Split Actually Does to Your Wealth
A stock split does not make you a dollar richer. The instant it happens, your holding is worth exactly what it was worth the second before. Everything
MarketsOct 7, 2026
Your Index Fund Is an AI Fund Now
You bought 505 stocks. The arithmetic says you effectively own about 48, and ten of them are close to one trade on artificial intelligence. That is the
AIOct 6, 2026
The Diderot Effect: How One Upgrade Triggers a Full System Rewrite
You did not buy a watch. You introduced a Breaking Change that forced a dependency cascade across your entire lifestyle stack.
Deep diveOct 1, 2026
Your 10 Percent Return Is Really 7 Percent, and the Gap Compounds
The S&P 500 returned about 10.15 percent a year from 1928 to 2025. After inflation, it returned 6.90 percent. That 3.25-point gap is the difference
FoundationsSep 30, 2026
Value Against Growth, a Hundred-Year Contest
One dollar in cheap value stocks in July 1926 became about 219,000 dollars by 2026. The same dollar in expensive growth stocks became about 17,000
Index InvestingSep 29, 2026
The Freedom Velocity Curve: Why 50% Is the Crossover Point That Changes Everything
A 10% savings rate chains you to work for 42 years. A 50% rate frees you in 15. The same salary. The same math. A completely different life.
Deep diveSep 24, 2026
Social Security Is Not Disappearing, but Current Law Cuts It About 20 Percent in 2033
Most young workers expect nothing from Social Security. The current-law baseline is not zero, it is a benefit cut of roughly a fifth around 2033, and the
RetirementSep 23, 2026
How Money Moves Through Sectors Across the Economic Cycle
Across 27 calendar years of S&P 500 sector data, last year's best sector repeated as this year's best only 12 percent of the time. The leaders and
MarketsSep 22, 2026
Individual Bonds or a Bond Fund, and Where the Real Difference Hides
Holding a bond to maturity feels safer than a fund that dropped 13 percent in 2022, but most of that safety is an accounting illusion, and the real
Inflation & Fixed IncomeSep 17, 2026
Why a 3x ETF Does Not Give You 3x the Return
A fund labeled "3x" tells you exactly one thing about its behavior, and it is not the thing most buyers assume. It promises three times the index return
FoundationsSep 16, 2026
The FIRE Formula Proof: Why Your Salary Doesn't Appear in Your Time-to-Freedom Calculation
The math is unambiguous. Income cancels out. Here is the step-by-step derivation that proves it.
Deep diveSep 15, 2026
International Stocks Lagged the US for Over a Decade, and Why That Is the Argument for Owning Them
A dollar put in the S&P 500 in August 2001 grew to about ten dollars. The same dollar in developed markets outside America grew to under five. Most
Index InvestingSep 10, 2026
What the CAPE Ratio Predicts Over the Next Ten Years
One valuation reading sat near the top of its range before the 1929 crash, again before the 2000 dot-com collapse, and again through the 2010s while the
MarketsSep 9, 2026
Your $350k Total Comp Is a Vanity Metric — Here's What Actually Measures Wealth
High income is throughput. Wealth is accumulation. The link between the two is not automatic — and the data proves it.
Deep diveSep 8, 2026
Annual, Quarterly, or Threshold Rebalancing, and What the Data Prefers
Leave a 60/40 portfolio alone for 46 years and it stops being a 60/40 portfolio. It quietly becomes a 95 percent stock portfolio, carrying far more risk
Asset AllocationSep 4, 2026
The Real Cost of a Luxury Car
A new Audi A7 loses $40,702 of its value in five years. A new Honda Accord loses $8,654. Both figures come from the same study of the same used-car
EngineeringSep 3, 2026
The Real Cost of Raising a Child
The most-cited number for raising a child in America is $233,610. It comes from a real government report, and it stopped being current a decade ago.
Life EventsSep 3, 2026
How to Invest Small Amounts of Money, and Why Spending Less Is Half the Engine
You do not need a lump sum to start. $50 a month becomes about $61k in 30 years; $500 becomes about $610k. The deposit is the one lever you fully control — and raising it moves more than chasing returns ever will.
FoundationsSep 2, 2026
You Are Trading a Non-Renewable Asset for a Renewable One — And Losing Every Time
Seneca identified the core asset misallocation problem 2,000 years ago. Modern engineers replicate it daily.
Deep diveSep 1, 2026
How Much Should You Bet When You Have an Edge?
There is a formula that tells you exactly how much of your money to put at risk, it has been public since 1956, and almost nobody should use the number it
AdvancedSep 1, 2026
Savings Account vs. Investing: Where Compound Interest Actually Shows Up
A high-yield savings account and a diversified index fund both compound. Feed each the same $500 a month for 35 years and one ends at $251k and the other at $901k. The gap is the whole argument.
FoundationsAug 29, 2026
The 2022 Bond Crash, and the Duration Arithmetic That Caused It
In 2022 a 10-year US Treasury lost about 15 percent. That is the worst calendar year for the safest asset in the portfolio since at least 1928, and it was
Inflation & Fixed IncomeAug 27, 2026
Should You Pay Off the Mortgage or Invest the Difference?
Prepaying a dollar of mortgage principal earns a guaranteed return equal to your mortgage rate. Investing that same dollar earns more on average and
Debt & SavingsAug 27, 2026
How the Rule of 72 Exposes the True Cost of Every Fee
A 1 percent fee sounds like a rounding error. Run it through one line of mental math and it turns a 7 percent return into a 6 percent return, which pushes
FoundationsAug 26, 2026
The Freedom Cost Matrix: What Your Car Choice Is Really Costing You in Years of Your Life
A BMW 3 Series costs $55,000 at the dealership. The real price — in the only currency that matters — is 8.6 years of your working life. Here is the derivation.
Deep diveAug 25, 2026
The S&P 500 Is Less Diversified Than Its Name Suggests
The number 500 in the S&P 500 promises a wide net. The weighting rule underneath it quietly hands most of your money to ten companies. By year-end 2025
Index InvestingAug 25, 2026
The Only Account the IRS Lets You Deduct, Grow, and Spend Tax Free
One account lets you deduct the money going in, grow it with zero tax, and pull it out tax free. The IRS built exactly one like that, and most people use
TaxesAug 20, 2026
I Fact-Checked an AI's Financial Advice
An AI-generated summary told me luxury cars lose 48.1 percent of their value in five years. The number is specific, plausible, and does not exist. No
AIAug 19, 2026
Golden Handcuffs: The Engineering Reason Why High-Earning Tech Workers Are Financially Fragile
A $400k salary without liquid reserves is not financial security. It is a well-funded fragility — and Nassim Taleb's framework explains exactly why.
Deep diveAug 18, 2026
The Yield Curve Has Called Nearly Every Recession Since the 1950s
One line in the bond market has flipped negative before every US recession in half a century, and it has never once told anyone the date. That line is the
MarketsAug 13, 2026
Is the 60/40 Portfolio Dead? A Century of Data Answers
In 2022 the 60/40 portfolio lost about 17 percent as stocks and bonds fell together, and a wave of headlines declared the strategy dead. The obituary was
Asset AllocationAug 12, 2026
The $23,250 Freedom Tax: How Your Commute Is Quietly Bankrupting Engineers
Most engineers calculate their compensation correctly and their commute cost completely wrong. Here is the full derivation — to the dollar.
Deep diveAug 11, 2026
The 4 Percent Rule, Where It Came From and When It Breaks
The 4 percent rule survived all but one 30-year period in a century of US market history. That single failure tells you exactly where the rule breaks and
RetirementAug 6, 2026
The Order of Your Returns Matters as Much as the Average
Two investors earn the same 30 yearly returns in a different order. One ends with 13.6 million dollars. The other runs out of money. Only the sequence
FoundationsAug 5, 2026
Your Financial OS Has the Wrong Root Constraint — Here's How to Rewrite It
Most engineers optimize for income or status. Both are corrupted root constraints. Here is the only one that produces freedom as a deterministic output.
Deep diveAug 4, 2026
The 401(k) in 2026: Get the Free Money First
Before any clever tax strategy, the 401(k) has one rule that beats them all: capture the full employer match. Here are the 2026 limits and how the account actually works.
Tax-Advantaged AccountsAug 4, 2026
Is This 1997 or 1999? The AI Bubble Question, Measured
In December 1996 the Fed chairman warned of irrational exuberance. Anyone who sold that day watched the S&P 500 double before the crash came. That episode
AIJul 30, 2026
The TFSA in 2026: The Account Most Canadians Should Fill First
The Tax-Free Savings Account is the rare account with no catch: money grows tax-free and comes out tax-free. Here is how the 2026 room works, and the mistakes that cost people.
Tax-Advantaged AccountsJul 30, 2026
The Fear Index Does Not Measure Fear
The number traders call the fear index measures no fear at all. It measures the price of S&P 500 options, and its worst readings have marked some of the
MarketsJul 29, 2026
The Fee Math That Explains Why Index Funds Win
A 1 percent annual fund fee sounds like a rounding error. On 100,000 dollars invested for 30 years at a 7 percent gross return, it quietly removes about
Index InvestingJul 29, 2026
The Man in the Car Paradox: Why Your BMW Has a Zero-ROI Signal
You spend capital to generate a signal. Engineering rule: a signal nobody receives has zero value. The data proves luxury cars fail this test completely.
Deep diveJul 28, 2026
The Traditional IRA in 2026: The Do-It-Yourself Retirement Account
The IRA is the retirement account you open yourself, no employer required. Here is the 2026 limit, when the deduction is actually allowed, and how it pairs with a 401(k).
Tax-Advantaged AccountsJul 25, 2026
Buy vs Rent, the Full Model Instead of the Slogan
Multiply a home's price by 5 percent, divide by 12, and compare the result to a month's rent. That single line decides more of the buy-versus-rent
HousingJul 23, 2026
The RRSP in 2026: A Tax Deferral, Not a Tax Break
The RRSP gives you a deduction today and taxes you later. That is a loan from your future self, and whether it is a good deal depends entirely on one comparison.
Tax-Advantaged AccountsJul 22, 2026
The Dunedin Study Reveals the One Variable That Actually Predicts Wealth — It's Not IQ
Why self-control beats stock-picking, six-figure salaries, and every optimization strategy you have ever considered
Deep diveJul 21, 2026
The Roth IRA in 2026: Pay Tax Now, Never Again
The Roth IRA takes after-tax money and never taxes it again, not the growth, not the withdrawals. Here is the 2026 limit, the income phase-out, and the backdoor for high earners.
Tax-Advantaged AccountsJul 17, 2026
What Bonds Actually Do When Stocks Crash, Every Major Drawdown Since 1929
In 2008 the S&P 500 lost about half its value, and 10-year Treasuries gained about 20 percent over the same months. That offset is the whole reason a
Asset AllocationJul 16, 2026
The FHSA in 2026: The Best of the RRSP and the TFSA
The First Home Savings Account gives you a tax deduction on the way in and tax-free money on the way out. For a first home, that combination is unmatched.
Tax-Advantaged AccountsJul 15, 2026
You Are Tracking the Wrong KPI for Your Own Wealth
Net worth is a lagging indicator. Savings rate is the only metric that actually predicts your financial future — and almost everyone has this backwards.
Deep diveJul 14, 2026
The HSA in 2026: The Only Triple-Tax-Free Account
The Health Savings Account is the only account that is deductible going in, tax-free while it grows, and tax-free coming out. Here is the 2026 limit and the stealth-retirement trick.
Tax-Advantaged AccountsJul 11, 2026
The Return Number Most Investors Never Check
Over the 30 years ending 2026, 10,000 dollars in the S&P 500 grew to about 110,000 on price alone and about 187,000 with dividends reinvested. Most
FoundationsJul 8, 2026
Why Time in the Exponent Is the Most Important Concept in Personal Finance (An Engineer's Explanation)
FV = P × (1+r)ⁿ tells you exactly which variable to optimize. Almost everyone optimizes the wrong one.
Deep diveJul 5, 2026
The Invisible Fee That Costs More Than Your Expense Ratio
Your fund's expense ratio is printed on every statement. The larger cost is not, and in a taxable account it can eat a quarter of your thirty-year balance
FoundationsJul 1, 2026
1% Better vs. 1% Worse: The Exponential Math Separating Wealthy Engineers from Broke Ones
Why small daily financial decisions are not small at all — and how to engineer the compounding forces in your favor
Deep diveJun 24, 2026
Why Starting 10 Years Late Costs You 50% of Your Wealth — Not 25%
The brutal arithmetic of doubling periods, and why no amount of catch-up saving can undo a delayed start
Deep diveJun 17, 2026
The Aviation Principle That Explains Why Most Engineers Never Achieve Financial Freedom
How a 1-degree error in your savings rate compounds into a financial canyon — and what it takes to correct your heading
Deep dive