Home & Big Purchases
Rent-vs-buy math, the real cost of owning a house or a car, down-payment strategy, and mortgage points: the decisions that shape your cash flow for decades.
30 guides in this topic
Strategy14 min read
Why Would a Millionaire Rent? What 2025 Fed Data Shows
About 3% of U.S. millionaire families rent, per the 2025 SCF. Who they are, why some rent by choice, and the after-tax math of renting vs. owning a home.
Concept23 min read
The Engineer Investor Housing Plan: Six Reforms, Graded Against the Evidence
Treasury puts the untaxed rental value of owned homes at $157B a year, over six times the mortgage deduction. Six graded reforms for supply, taxes and renters.
Strategy11 min readCalculator
Borrow or Sell for the Down Payment? Box Spreads, Pledged-Asset Lines and the Vest Bridge
For one modeled $100,000, three-month bridge, a box spread cost about $700 after tax; selling appreciated shares cost $7,400 or more. When borrowing wins.
Strategy14 min read
The Beach Rental That Cut Taxes and Lost Money: A 15-Year Case Study
A real beach rental held 2005 to 2020, with modeled costs: the sale cut one year's tax by $44,000, and the owners still finished $148,000 behind in cash.
Concept20 min read
Do Higher Interest Rates Cause Inflation? What the Evidence Says About the Fed's September Hike
Ackman says the Fed's September hike will raise inflation. Sixty years of identified-shock evidence says tightening lowers it. The live exception is rents.
Methodology17 min readCalculator
Is a 7% Mortgage High? What Fifty-Five Years of Data Can and Cannot Tell You
On September 17, 2026, a 6.95% mortgage sat at the 45.5th percentile of Freddie Mac's weekly record since 1971. Start the sample in 2000 and it is the 91st.
Concept16 min readCalculator
Are Property Taxes Regressive? Why the Denominator Changes the Answer
A viral chart says the median family pays 29x more property tax than the top 0.1%, relative to net worth. What that ratio measures, and what it misses.
Concept22 min readCalculator
What a $16,364 Rental Write-Off Is Actually Worth
For one modeled $600,000 rental owned by a couple earning $200,000, ten years of depreciation totaled $156,136 and cut their federal tax by $0.
Strategy11 min readCalculator
A 9% Mortgage Does Not Lose to 10% Stocks
On US stock returns 1928 to 2025, a guaranteed 9% beat the S&P 500 in 44% of ten-year windows and 4% of thirty-year ones. The threshold sits far below 10%.
Concept16 min readCalculator
Will the AI Boom Push Up Mortgage Rates?
A podcast pegs AI borrowing at $5T through 2029 and rates 250 bp higher. At a published deficit elasticity the same borrowing is worth about 0.7 pp on a mortgage.
Concept21 min readCalculator
How Much of a Ten-Year Treasury Yield Is Risk Compensation?
The NY Fed split a 4.77% ten-year in Aug 2026 into 3.98% expected short rates and 0.79% term premium. What the 0.79 pays for, and what it costs a homebuyer.
Strategy17 min readCalculator
One Employer, Four Exposures: Salary, Unvested Equity, Vested Stock, and Your Home
Four household exposures can move with one employer: salary, unvested grants, vested stock, and a mortgaged home. Only one of the four has a market price.
Strategy18 min readCalculator
BOAT: Break Out Another Thousand, and the Number That Tells You If It's Worth It
Run five boats through the full cost math and the loan payment is 27% to 31% of the total on conventional financing. Plus the break-even, in days per year.
Concept17 min readCalculator
Total Interest Is Not the Cost of a Loan
The $697,544 mortgage number that tells you almost nothing. Discounted at the loan's own rate, every term's payments are worth exactly what you borrowed.
Strategy16 min readCalculator
How Much Should You Spend on Vacation? A Percent-of-Income Anchor and Three Tests
Start near 3-5% of take-home pay, then test it on cash flow, liquidity and FI impact. At a 4% withdrawal rate, $1,000 a year of travel needs $25,000 invested.
Strategy16 min readCalculator
Will Demographics Crash Home Prices? What DIY Investors Should Know
Low birth rates and slowing household formation trim home-price appreciation by a modest amount. What the evidence supports, with a calculator.
Strategy20 min readCalculator
Rental Property vs. Global Index Funds: How Demographics, Leverage, Taxes, and Diversification Change the Math
Index funds are the better default for most DIY investors; a rental is a leveraged local business that must clear a hurdle. How demographics, leverage, and taxes decide it.
Strategy14 min readCalculator
Why a 50-Year Mortgage Won't Fix Housing Affordability
On a $400k loan at 6.5%, a 50-year term cuts the payment by near 11% and builds almost no equity for a decade. Why a lower payment is not affordability.
Strategy15 min readCalculator
Should You Buy or Lease a Car? What the Math Actually Says
Buying is not always better, and leasing is not always a rip-off. The deciding factor is how long you keep the car. The present-value math, the academic evidence, and a calculator.
Strategy17 min read
How Much House Can High Earners Really Afford? Three Frameworks, Three Answers
A $550K household qualifies for a $3.6M mortgage but comfortably carries closer to $2M. See how the lender, White Coat Investor, and balance-sheet lenses disagree by over a million dollars.
Strategy16 min readCalculator
Did Buying This House Beat Renting? 24 Years of Real Math
A home bought for $225K in 2002 is worth $500K today. The price return was 3.4% a year. Whether buying beat renting comes down to one number: 6.1%.
Concept17 min readCalculator
Do You Need a Paid-Off Home to Retire?
No, you do not need a paid-off home to retire, but you need durable, flexible cash flow. How a mortgage affects sequence risk, taxes, and FIRE math, with a keep-vs-payoff calculator.
Strategy14 min readCalculator
Funding the Down Payment: Gift, Family Loan, or Sell the Stock?
Where the down-payment cash comes from changes the tax and liquidity cost more than the monthly payment. Compare selling appreciated stock, a family gift, and a family loan for a high-income tech buyer.
Strategy16 min readCalculator
Are You About to Be House-Poor? A Stress Test for RSU-Heavy Households
Most home affordability calculators ask if you can make the payment. This one asks if you'll still be solvent if your RSUs drop 40% and a repair hits.
Strategy16 min readCalculator
Is a 30-Year Fixed Mortgage an Inflation Hedge? Yes, With Important Caveats
A 30-year fixed mortgage can hedge inflation, but only conditionally. Here's the math, Bernstein's four deep risks, and when the framing breaks down.
Strategy14 min readCalculator
Mortgage Points: When They're Worth It and When They're Not
Points prepay interest to buy down your rate. The CFPB break-even framework, who should buy them, and why shopping lenders usually beats it. With a calculator.
Strategy16 min readCalculator
The True Cost of Owning a Home: Cash, Economic, and Exit Value
Your mortgage payment is not your cost of ownership. Learn the three views (cash, economic, exit) used by HUD and CFPB, see the real categories most buyers underestimate, and use the interactive calculator to compute your own numbers.
Strategy14 min readCalculator
The True Cost of Owning a Car: Depreciation, Not the Monthly Payment
Depreciation is usually the largest cost of car ownership, and most buyers never see it. Learn the AAA/Edmunds TCO framework, see how gas, hybrid, and EV costs compare, and use the interactive calculator to find your real cost per mile.
Strategy16 min readCalculator
How Much to Put Down on a House: The Framework Most Buyers Get Wrong
Stop optimizing for total interest paid. The right down payment depends on cash to close, post-close reserves, PMI thresholds, and loan-bucket boundaries. Includes a calculator for tech workers with RSUs.
Strategy15 min read
Rent vs. Buy: A Financial Analysis Beyond the Monthly Payment
The monthly payment comparison is misleading. Learn how opportunity cost, transaction fees, tax benefits, and investment returns change the rent vs. buy math, and why hold period is the key variable.
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Disclaimer: This page is for educational and informational purposes only and is not financial, investment, tax, or legal advice. Summitward is not a registered investment adviser, broker-dealer, or financial planner, and no fiduciary relationship is created by your use of it. Consult a qualified professional before acting. Past performance and model projections do not guarantee future results. Provided as is, without warranty of any kind; see our Terms of Service for limitations of liability.