If you're under contract on a home in the Charleston area right now, your lender has probably asked you some version of this question in the last week. And if you're house-hunting, you've watched rates move faster than at any point in more than a year.
Here's where things stand. On September 16, the Federal Reserve raised its benchmark rate by a quarter point to a range of 3.75%–4.00% — its first increase since 2023 — and signaled that at least one more hike is possible this year. The next day, Freddie Mac's weekly survey put the average 30-year fixed at 6.95%, up from 6.76% the week before. That was the fourth straight weekly increase, the highest reading since January 2025, and the largest one-week jump in roughly sixteen months. A year earlier, the same survey was at 6.26%.
So: lock or float?
I'm going to give you a straight answer. But I want you to understand why, because the reasoning will serve you better than any headline. That means looking at the one number that actually drives mortgage rates, reading its chart honestly, and going back through the last half-century of inflation to see what history does — and doesn't — tell us.
First, the Fed doesn't set your mortgage rate
This surprises a lot of buyers. The Fed controls the overnight federal funds rate. Your 30-year mortgage is priced off something else: the 10-year U.S. Treasury yield, which trades under the ticker TNX.
Lenders take the 10-year yield and add a spread on top of it to cover the risks and costs of mortgage lending — prepayment risk, servicing, guarantee fees, and profit. Since the end of the Great Recession, that spread has averaged roughly 1.7 percentage points. It widened to about 3 points in 2023, when the Fed was shedding mortgage bonds, which is how mortgage rates briefly approached 8% even though Treasury yields were lower than they are today. Through late 2025 and into 2026, the spread has settled back to about 2 points.
So the working formula right now is simple:
10-year Treasury (~5.0%) + spread (~2.0 points) ≈ 30-year mortgage (~7.0%)
That's almost exactly where the market is. Which means if you want to know where mortgage rates are heading, the most useful thing you can do is look at TNX.
Reading the TNX chart: where the 10-year actually stands
A quick disclaimer before the chart talk. Technical analysis describes what price has done and where buyers and sellers have historically stepped in. It doesn't predict the future, and the bond market is ultimately driven by inflation, Fed policy, government borrowing, and global events. I'm a Realtor who watches this chart closely because my clients' payments depend on it — not a bond trader. Treat what follows as a map, not a forecast.
The trend: a steady climb since February
The 10-year yield opened 2026 around 4.15% and dipped below 4% in February. Then the conflict with Iran began, oil prices surged, and yields reversed hard. The path since then has been a textbook uptrend — a series of higher lows and higher highs:
- February: below 4.00% — the 2026 low
- Late April: weekly average around 4.30%
- May: touched 4.50%
- Late June: weekly average around 4.44% (a higher low)
- Mid-August: closed at 4.68% on August 14
- September 14: hit 5.00% for the first time since October 2023
- September 15: reached an intraday high of about 5.04% — the highest level since July 2007
- September 17: pulled back to 4.95% after the Fed decision
- September 18: back to roughly 5.00%
That's a move of about a full percentage point in seven months. As long as the pattern of higher lows holds, the primary trend is still up.
Resistance: the 5.00%–5.04% ceiling
This is the most important level on the chart right now.
In October 2023, the 10-year climbed to roughly 5% and stopped. It couldn't hold above that level, and it reversed sharply. Almost three years later, in September 2026, it ran back into the same zone, pushed to about 5.04%, and pulled back again.
When a market tests the same ceiling twice, years apart, and gets turned back both times, technicians call that major resistance. That's what we're sitting under right now.
There are two ways this resolves:
- If TNX fails here again — stalls, rolls over, and starts closing back below the mid-August level near 4.68% — that would suggest the 5% ceiling is holding, just as it did in 2023. That's the scenario where mortgage rates ease.
- If TNX breaks through and holds — especially a weekly close meaningfully above 5.04% — there's very little chart history overhead until the levels the 10-year last traded at in mid-2007, which I'd put roughly in the 5.25%–5.30% range. A confirmed breakout would open the door to mortgage rates in the mid-7s.
Support: where a pullback might find a floor
Below the current price, the levels I'm watching are:
- ~4.68% — the mid-August close, the last higher low before the run to 5%
- ~4.50% — the May level, roughly where yields paused earlier this year
- ~4.00% — the February 2026 low, the floor of the entire move
A drop to 4.68% would likely bring 30-year mortgage rates down toward the mid-6s. A drop to 4.50% would put them closer to 6.5%. Getting back toward 4% would require a genuinely different economic picture.
The momentum read
The move from 4.68% to 5.04% took about a month. That's a steep climb straight into major resistance. Steep advances into big ceilings often pause, consolidate, or pull back before the next leg, in either direction. That's not a prediction that rates are about to fall. It's a reason to expect volatility right here — which is exactly what you don't want while you're floating a rate.
What fifty years of inflation cycles tell us
You asked me to look back, so let's do it properly. Every major rate spike in modern history has been an inflation story, and each one ended a little differently.
1973–1981: The oil shock era
This is the period everyone reaches for when inflation shows up, and there's a real parallel to today. The 1973 oil embargo and the 1979 Iranian revolution both sent energy prices soaring, and inflation followed through the economy for years.
To break it, Fed Chairman Paul Volcker pushed the federal funds rate to about 20% by January 1981. The 10-year Treasury's weekly average peaked at 15.68% in October 1981. The 30-year mortgage peaked at 18.63% the week of October 9, 1981 — the highest reading in Freddie Mac's history.
It took a painful recession to get there. But once markets believed inflation was beaten, rates fell for most of the next four decades.
The lesson: oil-driven inflation can become entrenched if it spreads into wages and everyday prices. The peak in rates came when the Fed proved it would do whatever it took, not when it stopped hiking.
1994: The bond market's surprise
In 1994, the Fed raised rates aggressively and caught the bond market off guard. The 30-year mortgage rate climbed from under 7% in late 1993 to above 9% by the end of 1994 — a jump of more than two points in about a year.
Then inflation stayed contained, and rates came back down through 1995.
The lesson: a sharp rate spike driven by Fed hikes doesn't necessarily mean a new era of high rates. Sometimes the market overshoots, then corrects once it sees the Fed has things under control.
2007: The last time the 10-year was firmly above 5%
The 10-year yield last traded firmly above 5% in mid-2007. Then the financial crisis hit, and yields collapsed as money fled to safety.
The lesson: the highs in yields often come right before something breaks. But rates didn't fall in 2008 because of good news — they fell because of a crisis. That's not something anybody should be hoping for.
2021–2023: From record lows to 7.79%
The 30-year mortgage hit an all-time low of 2.65% in January 2021. Then pandemic-era inflation surged, the Fed began raising rates aggressively in 2022, and the mortgage-to-Treasury spread blew out to about 3 points. Mortgage rates peaked at 7.79% in October 2023, when the 10-year touched roughly 5%.
And then something important happened: the 10-year reversed hard. Within a couple of months it had dropped back to roughly the high-3% range, and mortgage rates fell back into the mid-6s by early 2024.
The lesson: the 5% level on the 10-year was the ceiling last time. Peak fear coincided almost exactly with the peak in rates.
2026: Where this cycle fits
Today's setup has pieces of all of the above.
Like the 1970s, the trigger is an oil shock tied to Middle East conflict. Oil has pushed above $100 a barrel, and the Strait of Hormuz disruption has no clear end date. Headline consumer inflation was 3.4% in August, with gasoline up 3.9% in a single month. Wholesale prices, measured by the PPI, rose 5.4% year over year.
But here's the crucial difference, and the reason I don't think this is 1979: core inflation — which strips out food and energy — was 2.4% in August, the lowest reading since March 2021. In the 1970s, energy inflation bled into everything. So far in 2026, it largely hasn't. That's the single most important fact in this whole analysis.
What has spread is the uncertainty — and bond investors are also demanding more compensation for the size of federal deficits and government debt. Those pressures can keep long-term yields elevated even if inflation cooperates.
Realistic expectations for the next three to six months
Nobody knows where rates are going. Anybody who tells you they do is selling something. But based on where TNX sits on the chart and what the fundamentals look like, here's how I'd frame the range of reasonable outcomes. These assume the mortgage spread stays near 2 points.
Most likely — chop near the ceiling. TNX trades roughly between 4.70% and 5.20% as markets digest each inflation report and the Fed's next move. Thirty-year mortgage rates bounce around between about 6.75% and 7.25%. This is the base case.
Relief — the ceiling holds. Oil prices ease, core inflation stays soft, and TNX rolls over from 5% the way it did in late 2023, falling back toward 4.40%–4.60%. Mortgage rates drift toward 6.4%–6.6%. If the spread also tightens toward its long-run average, rates could dip a little lower.
Stress — the breakout. Inflation surprises to the upside, the Fed hikes again, and TNX breaks and holds above 5.04%, heading toward the 5.25%–5.50% range. Mortgage rates move into the 7.25%–7.5% range — and if the spread widens again, as it did in 2023, rates could approach 8%.
What I'd consider unrealistic in the near term: a return to mortgage rates below 6% in the next six months. That would likely require the 10-year to fall below 4%, which in turn would probably take a meaningful economic slowdown or recession. It's possible. It's not a plan.
The calendar that matters
If you're deciding whether to float, these are the dates that can move TNX sharply:
- October 14 — September CPI inflation report
- October 27–28 — next Federal Reserve meeting, with the decision on October 28
- December 8–9 — final Fed meeting of 2026, with updated projections
- The first Friday of each month — the jobs report
If your closing date falls after any of these, floating means you're betting on the outcome.
So — should you lock?
If you're under contract with a closing date: I'd lock.
Here's the math that drives that answer. On a $345,200 loan — 80% of CTAR's August 2026 median sales price of $431,500 — principal and interest look like this:
- At 6.70%: about $2,227 a month
- At 6.95%: about $2,285 a month
- At 7.20%: about $2,343 a month
- At 7.45%: about $2,402 a month
Every quarter-point move is roughly $58 a month on that loan — about $700 a year, or around $21,000 over thirty years.
Now weigh the scenarios. In the best realistic case, floating might save you a quarter point. In the stress case, it could cost you half a point or more — and you'd be buying a Charleston home with a payment you didn't plan for, possibly with a debt-to-income ratio that no longer qualifies. With TNX pinned against major resistance and two major catalysts ahead in October, the risk is lopsided. When the downside is bigger than the upside, you lock.
A few things to ask your lender about when you do:
- Match the lock period to your real closing timeline. In South Carolina, your due diligence period, appraisal, and attorney-supervised closing all have to fit inside the lock. A 30-day lock is usually cheapest, but a 45- or 60-day lock may be worth the small extra cost if your timeline has any risk of slipping.
- Ask what an extension costs if closing gets delayed. It's much better to know that number now.
- Ask whether a float-down option is available. Some lenders allow a one-time rate reduction if rates fall meaningfully after you lock, usually for a fee. If you're genuinely torn, this is the best of both worlds.
If you're still shopping: don't let rate forecasts decide your purchase.
A pre-approval isn't a lock. You can't lock until you have a property under contract. So your focus should be on buying the right house at the right price, with a payment you're comfortable with today.
If the rate falls later, you can refinance. If it rises, you can't go back. That asymmetry is the whole reason I tell buyers not to wait for a perfect rate. I wrote about this in more detail in my article on timing the market and interest rates.
There are also ways to soften today's rate right now:
- Seller concessions and rate buydowns. In a market where homes are taking longer to sell, sellers are often willing to contribute toward a temporary or permanent buydown.
- Assumable loans. If a seller has a VA or FHA loan from 2020 or 2021, you may be able to take over their rate.
- Builder incentives. New construction communities around Summerville, Nexton, and the Clements Ferry corridor are frequently offering rate buydowns to move inventory.
Numbers to verify before you rely on them
- Rates change daily. Freddie Mac's 6.95% is a national weekly average for borrowers with 20% down and excellent credit, as of September 17, 2026. Your actual quote depends on credit, down payment, loan type, points, and the specific day.
- TNX levels cited here come from published market reports. The 2007-era resistance zone of roughly 5.25%–5.30% is my approximation and should be confirmed on a long-term chart.
- Historical figures for 1994 and late 2023 are approximate and drawn from general market history.
- The payment figures are my own calculations, principal and interest only — taxes, insurance, and HOA dues come on top, and in coastal Charleston that can be significant.
- The spread between the 10-year and mortgage rates can change independently of Treasuries. That's a risk to any forecast built on TNX alone.
I'm a Realtor, not a financial advisor or loan officer. Talk to your lender about your specific situation before making a lock decision.
The bottom line
The 10-year Treasury is sitting right under the same 5% ceiling that stopped it in 2023 — the highest it's been since before the financial crisis. It could hold there, as it did last time, and give buyers some relief. Or it could break through.
History says that peak fear often coincides with peak rates. But history also says nobody rings a bell at the top.
If you're under contract, lock and protect your payment. If you're still looking, focus on the house, not the headline — and keep the refinance option in your back pocket.
If you want help thinking through timing on your Charleston purchase, or you want me to connect you with local lenders who offer float-down options, give me a call.
Article written by :
Dustin Guthrie, Realtor
(843) 697-7757
[email protected]
