The boogeyman has returned.

Or so it feels like, as the 10-year Treasury yield briefly hit the much-discussed 5% level this morning. The market last flirted with this key threshold in October 2023, but the yield hasn't managed to settle above it since July 2007.

The return of the 5% yield is worrisome for people looking to buy homes-it indicates higher mortgage rates are coming-and for every U.S. taxpayer because a greater portion of public dollars will be needed to cover interest costs.

Yet investors must keep perspective: A 5% yield on the 10-year Treasury is not an economic monster.

"There is a lot of talk that a break above 5% on the US 10yr yield would be pivotal, and would generate macro and debt dynamic pressures," Padhraic Garvey, who leads ING's research team for the Americas, says. "But there is nothing mythical about 5%."

Its no more than a half percentage point premium over the 4% to 4.5% range considered standard for today's economy, he told Barron's.

Whether that premium matters depends entirely on the cohort being examined. Would-be homebuyers may sit out the housing market given the almost immediate trickle-through of higher 10-year yields to mortgage rates, but otherwise the finances of a majority of households remain in a decent shape.

Total debt payments, including mortgages and credit cards, as a percentage of disposable income has remained steady around 11% since late 2023. The first quarter reading was 11.2%, up over two percentage points from 2021, when some debt payments were paused due to the pandemic, but it remains below the prepandemic level and the all-time peak of 15.8% in 2007.

Debt payments are stable likely because millions of homeowners have locked in historically cheap fixed mortgage rates from the pandemic. That keeps them insulated from the move in 10-year yields. Mortgage payments make up 72% of all U.S. household debt.

Robust earnings provide companies a buffer from higher yields. Interest coverage ratio-a measure of how many times operating income can cover interest expense-is at a healthy level, too. On a median basis, S&P 500 constituents earn about 7.5 times more operating income than their interest expense. The higher the ratio, the better. The market has hovered around 6.5 to 7 times since 2025.

"Will 5% 10-year yield make a material difference vs say 4.5%? Probably not, in part because household and corporate balance sheets remain in good health," Ed Al-Hussainy, strategist at Columbia Threadneedle Investment, told Barron's.

"I would not expect aggregate consumption to weaken until we see higher unemployment first," he added.

And that's where the 5% boogeyman makes the difference. The effect of higher yields is seen in changing decisions: fewer people financing that car, fewer going for that Masters degree, fewer companies financing big growth initiatives, and some even shutting down funding for ongoing operations. Over time, higher Treasury yields affect the labor market and push lawmakers to make difficult choices between raising taxes or cutting benefit programs.

For now, the four-week average of claims for jobless benefits-a proxy for layoffs-continues to remain low at 206,000.

"We don't think there's any particular level(s) at which yields hamper growth," Deutsche Bank strategist Matthew Raskin told Barron's. "All else equal, tighter financial conditions slow the economy, but the impact of rising yields depends on why they're rising."

Even though inflation has been making more of a contribution off late, the true culprit behind the rise in bond yields this summer has been the so-called real yields. Its defined as the return on Treasury bonds minus expected inflation. Since the start of the war through last week, 10-year yields have risen 1.03 percentage points, and 0.91 percentage points or 88% of the rise has been because of real yields.

Conceptually, one can think of real yield as a sum of the anticipated future interest rates and term premium, which is simply the additional return investors want for holding riskier long-term U.S. bonds instead of safer shorter-term debt. Term premium has risen because of factors like solid economic growth, tougher competition from corporate bonds, more of which are now issued as long-duration, and a U.S. government that just hasn't shown a real inclination to arrest its budget shortfall.

"Growth vs. inflation vs. policy shocks have very different effects [on the economy]," Raskin says.

The same logic applies to stocks. Rising yields because of the rising amount of corporate debt tied to artificial intelligence spending and economic growth are not inherently negative for the stock market. But any rise in yields because of things like inflation put pressure on stocks.

For now, stocks are doing fine. When the 10-year yield hit 5% on Monday, the S&P 500 briefly fell nearly 1%, but it more or less stabilized in the hours after and is holding on to its 11% year-to-date gain. The corporate debt market is also okay as companies continue to pay a small amount in interest over Treasuries to attract investors.

"In the big scheme of things, there is a relative calm in corporate credit spreads. But there is a tipping point where some of the beta pressures act to darken the atmosphere in a more material fashion," Garvey writes.

No one can tell exactly how high yields can climb from here before something gives-sending stocks sliding and causing broad layoffs-but it's the speed of the ascent and cause that make a trend dangerous, not just the outright level.

These are worrying times.