Blended rate math, payment comparisons, and when each option makes sense — modeled at current rates.
If your first mortgage is above 5.75% — or you need to draw more than 85% of your first mortgage balance — a cash-out refi at 6.50% fixed almost always wins. If you’re sitting on a 4% rate and need a modest draw, the second lien wins on monthly payment. The math is clear. The risk is what most borrowers don’t price in.
Updated: March 2026 | Prime Rate: 6.75% | Non-QM second lien: ~9.50% variable | Defy cash-out refi: 6.50% fixed
For most borrowers, the choice between a second lien and a cash-out refinance comes down to one thing: whether you’re protecting a low rate — or paying for one.
Quick Answer: A cash-out refinance typically wins when your first mortgage rate is above ~5.75%, or when your draw exceeds ~85% of your first mortgage balance. A second lien is often cheaper on monthly payment when you have a low-rate first (≤4%) and need a smaller amount of cash. The catch: second liens are floating-rate products — what looks cheaper today can quietly become more expensive as rates move.
The scenario we see constantly: A borrower locked in a 4% rate in 2021. Home is now worth $750,000. They need $175,000 to fund a real estate acquisition. The second lien looks cheaper on paper — $1,385/month IO vs. resetting the full balance at 6.50%. They take the second lien. Eighteen months later, Prime has moved up 0.75%. Their payment is $1,516/month — and still floating. The cash-out refi they passed on would have been fixed at $1,385/month. Same number. But certain.
That’s the tradeoff. The math starts equal and drifts apart over time. At that point, the decision is no longer about cost — it’s about whether you’re willing to carry that uncertainty on an open-ended floating balance with no exit except refinancing anyway.
A second lien — typically a HELOC or home equity loan — is a loan taken behind your existing mortgage, usually at a higher variable rate tied to Prime. With Prime at 6.75% as of March 2026, Non-QM second liens are pricing at approximately 9.00–9.50% variable. Defy’s Non-QM cash-out refinances are pricing at approximately 6.50% fixed — though rates vary by borrower profile and market conditions.
This guide models the HELOC vs. cash-out refinance decision — and the second mortgage vs. refinance tradeoff — with real numbers. All comparisons use a 9.50% interest-only second lien (Prime 6.75% + 2.75% Non-QM spread, adjusting with market rates) and a 6.50% fixed cash-out refi. Payment comparisons are interest-only second lien vs. fully amortizing cash-out refi — an apples-to-oranges difference worth noting, since the IO second builds no principal while the refi amortizes from day one.
The Rate Structure
| Product | Rate Structure | Current Rate |
|---|---|---|
| 2020–2022 first mortgage | Fixed | ~3.00–4.50% |
| Current market first mortgage | Fixed | ~6.00–7.00% |
| Conventional HELOC (W-2, retail bank) | Prime + 0.50–1.50% | 7.25–8.25% variable |
| Non-QM second lien (self-employed, investor) | Prime + 2.25–2.75% | ~9.00–9.50% variable |
| Defy Non-QM cash-out refi | Fixed 30-year | 6.50% |
Non-QM borrowers pay a wider spread on second liens than W-2 borrowers — lenders price in the income documentation complexity. The second lien is fully floating. Every Fed rate move flows directly to the payment.
Scenario 1 — You Have a 4% First Mortgage
With a 4% first, the second lien wins on monthly payment for most draw amounts. The cheap first is worth preserving — until the draw grows large enough that blended cost of capital crosses the refi rate.
$400K Home, $200K First @ 4% | First P&I: $955/month
| Draw | 2nd IO/mo | Combined | Refi Balance | Refi Payment | Monthly Delta |
|---|---|---|---|---|---|
| $50,000 | $396 | $1,351 | $250,000 | $1,580 | 2nd saves $230/mo |
| $100,000 | $792 | $1,746 | $300,000 | $1,896 | 2nd saves $150/mo |
| $150,000 | $1,188 | $2,142 | $350,000 | $2,212 | 2nd saves $70/mo |
$600K Home, $280K First @ 4% | First P&I: $1,337/month
| Draw | 2nd IO/mo | Combined | Refi Balance | Refi Payment | Monthly Delta |
|---|---|---|---|---|---|
| $100,000 | $792 | $2,128 | $380,000 | $2,402 | 2nd saves $273/mo |
| $150,000 | $1,188 | $2,524 | $430,000 | $2,718 | 2nd saves $194/mo |
| $200,000 | $1,583 | $2,920 | $480,000 | $3,034 | 2nd saves $114/mo |
| $250,000 | $1,979 | $3,316 | $530,000 | $3,350 | 2nd saves $34/mo |
$800K Home, $350K First @ 4% | First P&I: $1,671/month
| Draw | 2nd IO/mo | Combined | Refi Balance | Refi Payment | Monthly Delta |
|---|---|---|---|---|---|
| $150,000 | $1,188 | $2,858 | $500,000 | $3,160 | 2nd saves $302/mo |
| $200,000 | $1,583 | $3,254 | $550,000 | $3,476 | 2nd saves $222/mo |
| $250,000 | $1,979 | $3,650 | $600,000 | $3,792 | 2nd saves $142/mo |
With a 4% first, the second lien wins on monthly payment in every scenario shown. The gap narrows as the draw grows — and that narrowing is exactly where the risk starts building.
In most cases, we recommend preserving the 4% first for draws under $150,000. Above that, run the full comparison — the monthly savings shrink, the rate exposure grows, and the case for resetting starts to matter.
The Blended Rate — Where the Math Shifts
When you carry a cheap first alongside a 9.50% second, your blended cost of capital is a weighted average. As the second grows toward the first balance, that blended rate rises toward — and eventually past — the 6.50% cash-out refi rate.
Blended rate: 4% first + 9.50% IO second (refi rate: 6.50%)
| Draw | Draw / First Ratio | Blended Rate | Refi Rate | Gap |
|---|---|---|---|---|
| $50K on $200K first | 25% | 5.10% | 6.50% | -1.40% — 2nd wins |
| $100K on $200K first | 50% | 5.83% | 6.50% | -0.67% — 2nd wins |
| $150K on $200K first | 75% | 6.36% | 6.50% | -0.14% — 2nd wins |
| $170K on $200K first | 85% | 6.53% | 6.50% | +0.03% — refi wins |
| $200K on $200K first | 100% | 6.75% | 6.50% | +0.25% — refi wins |
| $250K on $200K first | 125% | 7.06% | 6.50% | +0.56% — refi wins |
The crossover: in many modeled scenarios, the blended rate on both loans approaches or exceeds the cash-out refi rate once the second lien draw reaches approximately 85% of the first mortgage balance. The exact threshold varies based on amortization assumptions, closing costs, and loan terms — but the directional point is consistent: the larger the draw relative to the first, the weaker the case for keeping the cheap first. That’s before accounting for rate risk or equity build.
This pattern holds across home values. On a $280K first, the blended rate approaches 6.50% around a $235K draw. On a $350K first, around a $295K draw. Blended rate is one of the primary decision factors — not the only one; cash flow, liquidity needs, and tax treatment also play a role.
What this means practically: the larger the draw relative to your first mortgage, the harder it is to justify keeping the cheap rate. The math of preservation erodes as the need grows.
Scenario 2 — Your First Is at 5.75% or Above
For borrowers who originated in the current rate environment, there’s no cheap first to protect. The refi wins on monthly payment starting around $100,000 — and the advantage compounds from there.
$600K Home, $300K First @ 5.75% | First P&I: $1,751/month
| Draw | 2nd IO/mo | Combined | Refi Balance | Refi Payment | Monthly Delta |
|---|---|---|---|---|---|
| $50,000 | $396 | $2,147 | $350,000 | $2,212 | 2nd saves $66/mo |
| $100,000 | $792 | $2,542 | $400,000 | $2,528 | Refi saves $14/mo ✅ |
| $150,000 | $1,188 | $2,938 | $450,000 | $2,844 | Refi saves $94/mo ✅ |
| $200,000 | $1,583 | $3,334 | $500,000 | $3,160 | Refi saves $174/mo ✅ |
| $250,000 | $1,979 | $3,730 | $550,000 | $3,476 | Refi saves $254/mo ✅ |
With a 5.75% first, take the cash-out refi. It wins on payment starting at $100,000, grows to $254/month in your favor at $250,000, and locks your rate for 30 years. There’s no scenario at this rate where the second lien is the better long-term call.
The math isn’t close. The only question is timing.
Three More Reasons the Cash-Out Refi Case Strengthens as the Draw Grows
1. Rate Risk Compounds on Larger Balances
A second lien can look cheaper — until rates move. And when they do, you don’t get to lock them in. We routinely see borrowers with a 4% first take a second lien to preserve the low rate, then find themselves 18 months later with a second lien payment that’s risen $150–$250/month as Prime moved. The cash-out refi they passed on would have been fixed the entire time.
The second lien is floating. Prime moved 5.25% in the 2022–2023 cycle. Every Fed increase flows directly to the payment:
| Second Lien Balance | +0.50% Prime | +1.00% Prime | +1.50% Prime |
|---|---|---|---|
| $100,000 | +$42/mo | +$83/mo | +$125/mo |
| $150,000 | +$63/mo | +$125/mo | +$188/mo |
| $200,000 | +$83/mo | +$167/mo | +$250/mo |
| $250,000 | +$104/mo | +$208/mo | +$313/mo |
A $250,000 second at 9.50% today costs $1,979/month. If Prime returns to 8.50% — where it was 18 months ago — that payment becomes $2,292/month with no action on your part. The cash-out refi at 6.50% never moves. Over time, many borrowers find the second lien ends up costing more than they projected — not because the initial math was wrong, but because the rate didn’t stay where it started.
2. Interest-Only Builds Zero Equity
An IO second pays $0 in principal. The balance is identical in year 10 to day one. A cash-out refi amortizes from the start:
| Draw | IO Second — Principal Paid in 10 Years | Cash-Out Refi @ 6.50% — Principal Paid in 10 Years |
|---|---|---|
| $100,000 | $0 | $15,224 |
| $150,000 | $0 | $22,836 |
| $200,000 | $0 | $30,448 |
| $250,000 | $0 | $38,060 |
The larger the draw, the larger the equity gap.
3. Non-QM Second Lien Qualification Gets Harder at Higher Balances
Most Non-QM second lien programs cap at 80–85% CLTV. At larger draws, borrowers approach the ceiling. Income qualification on a second is also more conservative than on a first-lien cash-out refi — a self-employed borrower with $90,000 on their Schedule C may qualify for a bank statement cash-out refi at Defy on $200,000+ in annual deposits, while facing significant friction on a large second lien with the same documentation.
Decision Framework
Second lien is likely the better call if:
- Your first is at 4% or below and your draw is under 75% of the first balance
- You can qualify for the second at program terms
- You can absorb floating rate exposure on the balance
- Your draw need is short-term
Cash-out refi is worth running the numbers if:
- Your first is at 5.75% or above — the refi wins on payment starting around $100K
- Your draw approaches 85%+ of your first mortgage balance — blended rate math crosses
- You’re self-employed with write-offs that compress qualifying income for a second lien
- You want rate certainty — fixed vs. floating matters more as the balance grows
- You’re pulling equity from a rental property — a DSCR cash-out refi qualifies on rental income, not personal income
Non-QM Cash-Out Refi Programs at Defy
| Program | Who It’s For | Qualifying Income | Max LTV |
|---|---|---|---|
| Bank statement cash-out | Self-employed, business owners | 12–24 months deposits | Up to 80% |
| P&L cash-out | Business owners | CPA-prepared P&L | Up to 80% |
| DSCR cash-out | Real estate investors | Rental income only | Up to 80% |
| Asset depletion cash-out | High-net-worth borrowers | Liquid asset statements | Up to 75% |
| Foreign national cash-out | Non-U.S. residents | Foreign income docs | Up to 70–75% |
Quick Takeaways
- Second lien wins when your first is at 4% or below and your draw is under 75% of the first balance
- Cash-out refi wins when your first is at 5.75%+ at nearly any draw amount, or when your draw exceeds ~85% of a 4% first balance
- The 85% rule: blended cost of capital on a 4% first + 9.5% second crosses the 6.5% refi rate around that threshold
- Rate risk grows with balance: every 1% Prime increase adds $83–$208/month depending on second lien size
- IO second = zero equity: a cash-out refi amortizes $15K–$38K in principal over 10 years; an IO second pays $0
- Non-QM qualification: large second liens are harder to qualify for than a first-lien cash-out refi for self-employed and investor borrowers
Frequently Asked Questions
If I have a 4% mortgage, is a cash-out refi ever worth it?
On monthly payment, the second lien wins until the draw reaches roughly 85% of your first mortgage balance — at that point blended cost of capital crosses the 6.50% refi rate. Beyond payment math, the case for the refi strengthens on three factors: floating rate risk on a large second balance, zero principal paydown on an IO second, and qualification friction for Non-QM borrowers at higher second lien amounts.
What are Non-QM second lien rates in 2026?
Non-QM second liens are tied to Prime plus a spread — currently 9.00–9.50% for most Non-QM borrowers. Conventional HELOC borrowers with strong W-2 income pay Prime + 0.50–1.50%, or 7.25–8.25%.
Can self-employed borrowers do a cash-out refinance?
Yes. Defy’s bank statement cash-out refinance qualifies on 12–24 months of gross deposits — not tax return income reduced by write-offs. A borrower showing $90,000 on a Schedule C but depositing $200,000/year qualifies on the deposit history.
Can I do a cash-out refi on a rental property?
Yes. A DSCR cash-out refinance qualifies based on rental income — not personal income. This is the primary tool for investors pulling equity from existing rentals to fund additional acquisitions.
How much can I cash out?
Most Non-QM cash-out programs allow up to 80% LTV. On a $700,000 home with a $300,000 balance, that’s up to $260,000 in proceeds. Exact proceeds depend on appraised value, credit profile, and program.
How long does a Non-QM cash-out refi take to close?
At Defy, most Non-QM cash-out refis close in 14–21 days. Timeline is driven by appraisal and title, not income verification complexity.
Bottom Line
If you have a sub-5% first mortgage and need a modest draw, a second lien usually wins on short-term monthly payment — but introduces floating rate exposure with no equity build and no rate certainty.
If your first is above ~5.75%, or your draw is large relative to the first balance, a cash-out refinance is often the more stable and cost-efficient option — fixed rate, amortizing from day one, and frequently easier to qualify for at Defy’s Non-QM programs than a large second lien.
The cheapest option today isn’t always the cheapest over 3–5 years. That’s the math worth running before you sign.
Ready to Run Your Numbers?
The right answer depends on your first mortgage rate, balance, draw amount, and income structure. Defy will model both options side by side with your actual numbers.
Get a no-obligation comparison in 5 minutes — we’ll model the cash-out refi and second lien side by side with your actual rate, balance, and draw amount. Schedule your consultation with Defy Mortgage.
