What a $100K Down Payment Could Become in the Stock Market

When you make a down payment on a home, that cash stops working for you in the stock market. But it doesn’t just sit there either. Leverage means your $100,000 controls a $500,000 asset. So what actually happens on each path?

All numbers below use our calculator’s default assumptions: $500,000 home, 20% down, 6% mortgage rate, 3% appreciation, $2,500/month rent, 7% investment return.

The homeownership path: leverage is real

Your $100,000 doesn’t grow at 3%. It controls a $500,000 home that appreciates at 3%. In year one, 3% on $500K is $15,000 in appreciation, a 15% return on your $100K equity. You’re also paying down the mortgage, building equity from both directions.

Here’s how your equity actually grows:

Year	Home Value	Mortgage Balance	Your Equity
1	$515,000	$395,000	$120,000
5	$580,000	$372,000	$207,000
10	$672,000	$335,000	$337,000
20	$903,000	$216,000	$687,000
30	$1,214,000	$0	$1,214,000

That $100K becomes $1.21 million in gross equity. Leverage is powerful.

But to access that equity, you have to sell. After 6% selling costs ($73,000), your net equity is $1,141,000. That’s buyer net worth: what the calculator reports.

The renter-investor path: compounding + contributions

The renter invests the $100,000 down payment and also invests the money saved each year by renting instead of owning. At default assumptions, owning costs about $46,600/year in year one while renting costs about $30,200. That $16,400 difference gets invested too, and it grows over time as ownership costs rise faster than rent.

Year	Annual Cost to Own	Annual Cost to Rent	Difference Invested	Portfolio Value
1	$46,600	$30,200	$16,400	$120,000
5	$48,800	$34,000	$14,800	$226,000
10	$52,000	$39,400	$12,600	$395,000
20	$60,000	$52,900	$7,100	$916,000
30	$70,700	$71,100	-$400	$1,851,000

The renter’s portfolio reaches $1,851,000. That’s renter net worth: fully liquid, no selling costs.

Notice something interesting: by year 30, annual owning costs ($70,700) and annual renting costs ($71,100) are nearly identical. The renter’s advantage is built almost entirely in the early and middle years when the cost gap is widest.

The real comparison

	Buyer	Renter-Investor
Net worth at year 30	$1,141,000	$1,851,000
Liquid assets	$0 (all in the house)	$1,851,000

The renter-investor ends up ahead by roughly $710,000. This matches our calculator’s default output.

Why the gap is so large

It’s not just about 7% vs. 3%. Three forces compound against the buyer:

Ownership costs are substantial. Over 30 years, the buyer pays ~$464,000 in mortgage interest, plus $350,000+ in property taxes, insurance, and maintenance. Those dollars build zero equity.
The renter invests the difference early. The cost gap is widest in the early years ($16,400/year) when the renter’s investments have the most time to compound. By year 30, costs converge, but the portfolio is already large.
Compounding is exponential. Early contributions matter most. The renter’s portfolio growth accelerates over time as returns compound on a larger base.

When leverage tips the scales toward buying

Leverage favors the buyer when:

Appreciation is high. At 5% appreciation instead of 3%, the home reaches $2.16M and buyer net worth jumps significantly.
Mortgage rates are low. At 4% instead of 6%, less money goes to interest and more to equity.
Rent is high relative to ownership costs. If rent were $3,500/month instead of $2,500, the renter has much less to invest.

In high-appreciation, low-rate markets, buying can win. But at current rates and national averages, the math favors renting and investing.

Compound growth at different return rates

The choice of return rate drives the entire analysis. Here is what $100,000 grows to under different assumptions over 10, 20, and 30 years (compound interest formula applied; S&P 500 historical nominal return sourced from NYU Stern/Damodaran dataset):

Return Rate	$100K after 10 yrs	$100K after 20 yrs	$100K after 30 yrs
5% (conservative)	$162,889	$265,330	$432,194
7% (moderate, real return)	$196,715	$386,968	$761,226
10% (S&P 500 historical nominal)	$259,374	$672,750	$1,744,940
3.5% (home appreciation, FHFA HPI)	$141,060	$198,979	$280,679

A note on the 7% figure: that is a commonly used estimate for the real (after-inflation) long-run return on U.S. equities. The nominal S&P 500 return is closer to 10% historically. The 3.5% home appreciation rate comes from the Federal Housing Finance Agency House Price Index (FHFA HPI), which tracks long-run national average appreciation.

The gap between 3.5% and 7% is striking on a 30-year horizon: $280,679 versus $761,226. And the home is not actually growing at 3.5% on just the $100K: it is growing on the full $500K. That leverage argument needs to be addressed directly.

The leverage comparison done honestly

Home buyers often respond to the above table by pointing out that the home appreciates on the full $500,000 purchase price, not just the $100,000 down payment. That is correct, and it matters. Here is what home equity actually looks like at different appreciation rates over 30 years (starting from a $500K home, 20% down, 30-year mortgage, 6% rate, and 6% selling costs applied at sale):

Appreciation Rate	Home value yr 30	Equity net of selling costs	Down payment invested at 7%
2%	$905,000	~$760,000	$761,226
3.5% (FHFA national avg)	$1,406,000	~$1,177,000	$761,226
5%	$2,160,000	~$1,812,000	$761,226

At 2% appreciation, leverage barely helps: the unlevered index fund investment at 7% essentially matches the home equity outcome. At 3.5% (the FHFA national long-run average), home equity exceeds the down payment investment alone by a wide margin. At 5%, home leverage wins decisively.

This table, though, compares only the down payment capital in isolation. The full picture (which the calculator models) includes the annual cost difference between owning and renting each year, and what happens when those savings are invested. That is where the renter’s full advantage emerges, particularly in the early decades when ownership costs significantly exceed rent.

The discipline question: two scenarios

Everything above assumes the renter actually invests the difference. Every month. For 30 years. No dipping into the account for vacations, cars, or emergencies.

A mortgage enforces savings whether you are disciplined or not. That is its hidden superpower. If you would not invest the difference, forced equity through homeownership might be your best wealth-building tool by default.

But the consequences of discipline level are dramatic. Consider two renters, both of whom invest the $100K down payment at 7%:

Scenario 1: Fully disciplined renter. Invests $100K upfront and adds $1,367/month (approximately the average monthly cost savings in the early years of this comparison). After 30 years, the portfolio reaches approximately $1.85 million. This is what the calculator’s default output models.

Scenario 2: Partially disciplined renter. Invests $100K upfront but only contributes $300/month consistently (perhaps spending the rest on lifestyle upgrades). After 30 years, the portfolio reaches approximately $1.18 million.

Compare both to the buyer’s net equity of approximately $1.14 million at 3.5% appreciation. The fully disciplined renter ends up $710,000 ahead. The partially disciplined renter ends up roughly even with the buyer; close enough that the buyer’s non-financial benefits (stability, customization, community roots) could reasonably tip the decision toward buying.

The honest question is not just “what does the math say?” but “what will I actually do?” The calculator answers the first question. Only you can answer the second.

What $100K looks like in different cities

The same $100,000 creates very different leverage situations depending on local home prices, and that changes the entire analysis.

Austin, Texas. The median home price is approximately $550,000 (Zillow Research, early 2026). A $100K down payment represents about 18% down, avoiding PMI but leaving a $450,000 loan. Monthly mortgage payments at 6% would be approximately $2,698. Rent for a comparable property is roughly $1,800-$2,200/month. The cost gap favoring renting is moderate.

Cleveland, Ohio. The median home price is approximately $200,000. A $100K down payment is 50% down, resulting in a $100,000 loan and monthly payments of approximately $600 at 6%. Rent for a comparable home runs roughly $1,200-$1,500/month. In this market, owning can actually cost less than renting, which reverses the renter’s monthly savings advantage entirely.

San Francisco, California. The median home price exceeds $1.2 million. A $100K down payment is barely 8% down, triggering private mortgage insurance (PMI) typically costing 0.5-1% of the loan balance annually. Monthly carrying costs on a $1.1M loan at 6% approach $6,600, plus property taxes averaging over $12,000/year and PMI of roughly $550/month on top of that. A comparable rental might cost $3,500-$4,500/month. Here, the renter’s savings advantage is enormous, and the opportunity cost of deploying $100K as a down payment (rather than into the market) is compounded by the fact that it is not even enough for a 20% down payment.

These three examples illustrate why the calculator matters. The same $100K down payment can represent dominant leverage in one city and a thin, PMI-triggering contribution in another. Your specific local market, rent levels, and mortgage costs change the outcome more than any national average does.

Frequently Asked Questions

Is the stock market comparison fair since real estate uses leverage? It is a fair concern. The comparison in this article is specifically about the down payment capital: what happens to $100K in two different uses. The home leverages that $100K to control a $500K asset, but it also requires ongoing mortgage payments that the investor does not face. A complete comparison (which our calculator provides) accounts for both the leverage advantage and the ongoing cost disadvantage.

What if the stock market crashes right after I invest my down payment? Market volatility is real. In any given 5-year period, the stock market can lose 30-50%. But over 20-30 year periods, the S&P 500 has never produced a negative return (Damodaran dataset, NYU Stern). The risk of a bad sequence of returns is real for short-horizon investors, but for someone deploying a down-payment-sized investment with a 20-30 year horizon, the long-run probability of outperforming home appreciation is high.

Should I put a smaller down payment and invest the rest? Possibly. Putting 10% down instead of 20% frees up $50K to invest, but requires paying private mortgage insurance (PMI), typically 0.5-1% of the loan annually, until you reach 20% equity. The PMI cost versus the investment return on the freed capital is a tradeoff worth calculating for your specific loan and rate situation.

How does this change if I put the money in a Roth IRA? A Roth IRA adds a tax advantage: all growth is tax-free. At a 7% return, $100K in a Roth IRA becomes approximately $761K tax-free after 30 years. The same return in a taxable brokerage account would owe capital gains tax (15-20%) on the gains. This makes the Roth IRA version of the strategy even more favorable relative to home equity, which does have its own tax advantage (the capital gains exclusion on primary residence sale, currently $250K single / $500K married per IRS Publication 523).

The math in this article is based on national averages and standard assumptions. Your local market, income, tax situation, and investment behavior all shift the outcome. Use the Rent vs. Buy Calculator to model your specific numbers and see exactly where the two paths diverge for your situation.