On August 19, the U.S. Treasury published an out-of-schedule announcement of long-end buyback expansion. Bitcoin rose sharply immediately after the announcement, liquidating over $1B in short positions within hours. This led to a 10% breakout the same day and 20% during the following 48 hours, as shown below. The SEC and Trump announced crypto-friendly messages around this time also but their effects on the price are less obvious on the chart. The Treasury’s message came with U.S. debt already above 120% of GDP. It signals more active debt management, raising the prospect of financial repression. That possibility gives investors a reason to shift funds from U.S. debt into alternatives such as Bitcoin.

Why a High Debt/GDP Ratio Must be Controlled

Macroeconomically, the U.S. government aims to promote steady real growth with modest inflation. This has been the case for most of the past three decades. The chart below shows this “dance” between inflation (x-axis) and real growth (y-axis). During the crises of 2008 and 2020, the economy deviated sharply, requiring major policy rescues to pull it back toward the healthy region around 3% real GDP growth and 2% inflation.

The government can operate at a deficit, especially in crisis when spending rises and tax revenue falls. In such situations, it draws on its credibility to borrow money from investors, who demand an interest rate reflecting their opportunity cost and confidence in the government. During good years, fiscal surpluses can be used to repay debt and strengthen the government’s credibility. In reality, however, the U.S. debt/GDP ratio rose sharply over the last two decades, particularly during the two major crises. Debt interest payments have also risen noticeably as a share of GDP in recent years, as shown below.

A high debt/GDP ratio can be dangerous because the investors can abruptly lose confidence, leading to skyrocketing borrowing costs and leaving the economy far more vulnerable to crises and economic collapse. A 2010 IMF model estimated a U.S. debt limit of roughly 173% of GDP. Even without a crisis, high debt makes inflation more likely and harder to control (BIS; Banerjee et al.).

Debt Control Options

Let D be the total debt at the beginning of the year and ΔD its increase over the year. Controlling debt means controlling ΔD. In general, ΔD has two components:

ΔD = I + PD

Here, I is the interest paid to investors, and PD is the government’s primary deficit — spending excluding debt interest, minus tax revenue.

Reducing PD requires lower spending or higher tax revenue. In practice, however, cutting spending and raising taxes can meet strong opposition, and aggressive austerity can hurt growth.

For a given debt stock D, reducing I means lowering the interest rate r = I/D. Research has found that the investors’ opportunity cost — the return rate m they can get elsewhere — is usually higher than r. This means the investors usually take a loss to buy the debt. This gap of D*(m-r) is the investors’ loss but the government’s gain. It is called the debt revenue.

The investors accept a low debt rate r for two reasons:

- Voluntarily, for the debt’s merits, such as predictable cash flow, large market size, deep liquidity.

- Involuntarily, due to captive policies that require certain institutions to hold government debt or make alternative investments inconvenient or illegal. These policies, together with market interference to push down r, constitute financial repression.

Because the return investors could earn elsewhere, m, is usually higher than the nominal GDP growth rate g, we can use g as a conservative estimate for m. This gives the following estimate of debt revenue:

DR = D*(g-r).

The first figure below shows the historical walk between the primary deficit PD (x-axis) and debt revenue DR (y-axis), both expressed as percentages of GDP. Note that when PD=DR, the debt/GDP ratio stays unchanged. The primary deficit dominates in years of active fiscal rescue and slow growth (2009, 2020), while debt revenue dominates in years of strong growth or financial repression (1951, 2000, 2022). The second figure shows the impact on the debt/GDP ratio.

Parsing the Treasury’s Message

The high debt/GDP ratio has renewed discussion of financial repression (Jafarov et al.; Mullin; Bolhuis et al.). Amid competition from AI-related borrowing, long-term borrowing costs for new debt had just reached a 25-year high on August 13. Treasury’s August 19 buyback expansion, which can help lower borrowing costs, seemed like a response to the rising borrowing costs. The unscheduled timing was surprising because it deviated from the Treasury’s stated principle of being “regular and predictable” and can potentially increase borrowing costs in the long run. This signals a willingness to intervene more actively. For debt investors who see this as a step toward financial repression, it strengthens the case for diversifying into alternatives such as Bitcoin.