Here’s a number that should stop you cold.
The $1.0 trillion the federal government is projected to spend on interest payments this fiscal year is more than it is expected to spend on national defense ($947 billion), Medicaid, veterans’ benefits, transportation, education, and energy — combined.
One trillion dollars. Just to service debt that already exists. And the S&P 500 is within reach of all-time highs.
That disconnect is either the most important thing in markets right now, or the most irrelevant. The argument for irrelevant is that it’s always been this way — debt grows, markets ignore it, equities win. The argument for important is that we’ve never quite been here before.
The Numbers Are Not Subtle
The debt totaled $39.2 trillion in June 2026, underscoring how quickly the total can rise when deficits persist and borrowing costs move higher. The deficit totals $1.9 trillion in fiscal year 2026 and grows to $3.1 trillion by 2036. Relative to the size of the economy, the deficit is 5.8 percent of GDP in 2026, rising to 6.7 percent in 2036. Deficits averaged 3.8 percent of GDP over the last 50 years.
So we’re running deficits nearly 50% above the historical average — in a period of decent economic growth, with no world war, no active pandemic. That’s the part that doesn’t fit the old models.
The rapid accumulation of federal debt, in addition to higher interest rates, has pushed up the federal government’s cost of borrowing. Through the eighth month of FY26, interest payments on the national debt have been 8.8 percent higher than the previous year.
The Slow Bleed Nobody Prices
This is the part Wall Street consistently skips. Not a crisis moment. A slow, compounding erosion of fiscal flexibility that eventually shows up in yields, then in discount rates, then in equity multiples. The sequence doesn’t move fast enough to generate a CNBC headline. It just grinds.
CBO projects that interest payments will grow from $1.0 trillion (3.3 percent of GDP) in fiscal year 2026 to $2.1 trillion (4.6 percent of GDP) by 2036. Over the 2026-2036 budget window, interest payments will grow faster than any other major budgetary category, increasing by 106 percent.
Think about that trajectory for a second. Interest costs doubling in ten years. Over the same period, interest will exceed Medicare spending by FY 2028 and defense and nondefense discretionary spending by FY 2038. The federal government will eventually spend more servicing the past than investing in the future.
Yields on 20-year and 30-year U.S. Treasuries both briefly surpassed the 5.1% threshold recently, drawing heightened attention to a sustained selloff in long-dated government bonds. This surge in yields reflects deepening market concerns over the United States’ widening fiscal deficit, rising debt levels, and mounting interest burdens.
Why Equities Haven’t Reacted
A few reasons. First, earnings are still growing. Earnings growth expectations are rising and broadening beyond mega-cap tech stocks, supported by AI-driven investment and improving momentum across small-cap, value, and emerging markets. Strong earnings are a powerful distraction from a deteriorating fiscal backdrop.
Second, this isn’t new. Debt has been rising for 25 years and equities have kept climbing. Recency bias is a real force.
Third — and this is the honest answer — the timing is genuinely unknowable. The assumption that financial markets will continue to believe Congress and the White House will eventually restore fiscal sustainability holds until it no longer mathematically can. But once that faith is shaken, timelines shrink fast.
What Actually Changes the Calculus
The mechanism that converts a fiscal slow-burn into a market event runs through the bond market. Escalating risk tied to the nation’s debt obligations could push investors to require higher yields on Treasuries, forcing interest rates up, which would make the deficit even more difficult to resolve. Should enough investors back out of buying Treasuries, the Federal Reserve would step in as a buyer of last resort — a dynamic that might accelerate the government’s debt spiral by further eroding confidence in the U.S. economy’s stability.
That’s the chain. Yields up. Borrowing costs up everywhere — mortgages, corporate debt, auto loans. Consumer spending slows. Corporate margins compress. Equity multiples contract. The fiscal problem becomes an economic problem becomes a market problem.
We’re not there. But the distance is shorter than it was three years ago.
What Investors Are Missing
National debt can affect investors through interest rates, bond yields, stock valuations, and future policy choices. If investors demand higher yields to buy Treasury securities, borrowing costs can rise across the economy and bonds can compete more directly with stocks for investor dollars. If growth remains resilient and Treasury demand stays steady, debt can remain a long-term risk rather than an immediate market disruption.
That last line is the key. The base case still holds. The risk is in the tail — a demand shock in Treasuries, a credit rating action, or a failed debt auction that forces the market to price in what the fiscal data has been saying for years.
Much of the recent margin strength appears driven by pricing power in sectors like technology, semiconductors, and energy, which can be harder to sustain over the long term. Layer a rising cost of capital on top of margin pressure and the valuation math gets uncomfortable quickly.
The Positioning Implication
This isn’t a call to sell equities. It’s a call to think about what you own inside them. Long-duration, high-multiple growth names are most exposed to a yield re-rating. Short-duration cash flows — financials with floating-rate assets, commodity producers, businesses with pricing power against inflation — hold up better in that scenario.
Real assets. Shorter duration. Lower multiple. These aren’t exciting trades. They’re just the ones that make sense if the bond market finally decides to have the conversation the fiscal data keeps demanding.
The debt will keep growing. The only question is when markets decide that matters.
For informational purposes only.
