Maintaining the international stability of the Hryvnia

In conventional open-economy macroeconomics, a small open economy seeking to stabilise its exchange rate relative to a major reserve currency (say, the US dollar or euro) typically depends on (i) sufficient foreign exchange reserves, (ii) credible commitments to monetary and fiscal discipline, (iii) foreign borrowing or aid flows that buttress the central bank’s balance sheet, and (iv) hedging or derivative markets to smooth demand for foreign exchange. In effect, the country builds a buffer zone such that speculative pressures can be soaked up without the exchange rate collapsing.

In Ukraine’s case, the US-backed element enters not through a literal peg contract with US Treasury bonds, but via donor-based injections of foreign currency, US participation in multilateral support, and the confidence effect such backing confers. The extent of this anchoring depends on the scale, timing, and reliability of external financing relative to Ukraine’s underlying external vulnerability and monetary regime design.

In the following, we first quantify the external exposure and reserve magnitude, then map the mechanisms by which stabilisation is pursued, analyse the theoretical constraints, and finally evaluate the sustainability and risks.

Quantitative Context: External Vulnerabilities and Reserve Capacity

External Pressures and Financing Needs

Ukraine is structurally exposed on its external side: it commonly runs trade and current account deficits because its export base (especially in wartime) is constrained, while imports (especially for defence, reconstruction, energy) remain large. At the same time, debt service and import dependence imply that foreign currency demands are recurring.

Several studies and policy commentaries highlight that foreign aid has been essential for Ukraine to plug her gaps and sustain macro stability. For instance, the CEPR argues that without continuing external transfers, the government would face acute shortfalls in meeting her trade and fiscal obligations. 

Ukraine has also accumulated large amounts of financial aid (loans, grants, guarantees) from US and Western sources. For example, as of recent years, US support (through direct financing and via multilateral institutions) has run into tens of billions of dollars. 

Therefore the available “buffer” depends heavily on these flows being timely and sustained.

Magnitude of Reserves and Intervention Capacity

The National Bank of Ukraine (NBU) publishes data on its international reserves, defined as liquid foreign currency assets and gold that can be used for interventions and sovereign payments. 

As of end-September 2025, reserves stood at about USD 46.5 billion. This is a nontrivial number and suggests that the NBU currently has meaningful capacity to intervene in foreign exchange markets (i.e. to sell dollars in periods of UAH depreciation pressure). In recent months, reserves have also shown some variability (increasing from USD 46.0 billion in August to USD 46.5 billion in September per NBU data), and other sources (e.g. TradingEconomics) report about $46.5 billion in September 2025 as well. 

However reserves are not infinite buffers, and their adequacy depends on the scale and frequency of attacks on the currency. If capital flight or speculative pressure intensifies, the depletion of reserves may force sharp adjustments.

In practice, the NBU does conduct currency interventions. The NBU itself monitors and reports on its intervention operations (buying or selling foreign currency in the interbank market) to moderate volatility. 

A speech by the NBU Governor noted that in periods of lower net demand for FX (from households or businesses), the NBU reduced net sales of foreign currency, which helped preserve reserves. 

In sum, Ukraine is currently better positioned (in terms of reserve scale) than it was during earlier crises, but the margin of safety is still constrained by the magnitude of external pressures.

Mechanisms of Stabilisation and US-Backed Support

Here we formalise how the NBU and Ukraine deploy the “stabilisation toolkit,” and highlight the role of US/Western support within that framework.

1. Foreign Exchange Interventions (Spot and Structural Trades)

The central bank engages directly in the FX market: selling foreign currency (USD/EUR) when UAH is under downward pressure (i.e. when there is excess dollar demand), and buying FX when there is excess supply. These operations smooth short-term volatility and help anchor near-term expectations.

Because the NBU holds foreign reserves, these sales are backed by hard assets. The central bank thus acts as a “shock absorber”. The scale of such interventions must be calibrated: too small, and they won’t sway speculative dynamics; too large, and risks depleting reserves rapidly.

To maintain credibility, the NBU must also show that it has adequate reserves and that it will not run out of ammo. The mere announcement (or market awareness) that large US/Western support is available serves as a deterrent to speculative attacks.

2. Forward, Hedging, and Derivative Instruments

To reduce pressure on spot markets, participants—importers, exporters, firms—may hedge future forex needs via forward contracts, non-deliverable forwards (NDFs), options, or swaps. This allows part of the currency demand to shift off the spot markets into more predictable time structures.

In 2025, Ukraine has introduced regulatory adjustments (e.g. NBU Regulation No. 95) to broaden the scope for residents to use forward contracts (deliverable and non-deliverable) to hedge currency exposure. Under this framework, banks must hold matching positions to avoid buildup of unhedged net risk. (These hedging markets thus act as a stabilizing buffer on speculative demands.)

When derivative markets are liquid and deep, they reduce margins for “panic” flows in the spot market.

3. Capital Controls, Restrictions, and Prudential Limits

In extreme phases, Ukraine has used capital controls—limiting FX withdrawals, restricting cross-border flows, or imposing reserve/mandatory FX retention rules. Early in the 2022 war phase, the NBU temporarily fixed the exchange rate and imposed limits on FX withdrawals to avoid desperate capital flight. 

Over time, these controls have been phased down, but the possibility remains as a tool of last resort.

In addition, banks and corporates are subject to regulatory constraints on open FX positions, matching requirements, and margin/loan-to-FX-exposure limits. These prudential measures limit speculative or runaway currency mismatches.

4. Accumulation and Strategic Use of International Aid/Grants/Loans

This is where US and Western support plays a direct operational role. When the US or allies deliver foreign currency grants, loans, or guarantee lines, some portion can be converted (or transferred) into central bank reserves, bolstering the NBU’s capacity to intervene. In effect, external financing acts as reserve replenishment.

For example:

• US grants or aid provided in dollars (or euros) increase the supply of foreign currency available to authorities, reducing pressure on the NBU’s reserves or even enabling reserve buildup.

  
  

• Multilateral loans or credit lines (e.g. IMF, World Bank) can be drawn and used to bolster Ukraine’s external buffers. The U.S. often supports or seeds these institutions, thereby influencing the volume and timing of disbursements.

  
  

• Confidence effect: Knowing that further US/Western support is available helps damp speculative pressure by reducing tail risk.

Thus although Ukraine does not issue US Treasury-backed currency guarantees, in a functional sense, the US support enhances the credible capacity of the NBU to act.

In practice, the US has committed substantial support to Ukraine: multiple aid packages total in the hundreds of billions of dollars (when including military, humanitarian, and budgetary transfers). 

Some of this support is channeled via mechanisms such as the USAID Multi-Donor Trust Fund (MDTF) or dedicated US trust funds, which pool donor resources for direct programmatic and budgetary support. 

Because a proportion of this support is fungible (i.e. it relieves pressure on domestic revenue or external borrowing), it strengthens Ukraine’s ability to maintain macro stability and thus reduces the temptation toward monetary financing or resorting to uncontrolled devaluation.

5. Macroeconomic Discipline and Signaling

Finally, currency stabilisation is not purely a technical or operational affair—it is deeply tied to the credibility of monetary and fiscal policy:

• The government must avoid excessive deficits or monetisation, which would undermine confidence in the currency and generate inflationary expectations.

  
  

• The central bank must anchor inflation expectations (e.g. via a credible inflation target) so that currency holders do not preemptively dump UAH.

  
  

• Structural reforms (trade liberalisation, export support, transparency) help reduce risk premiiums and bolster long-run confidence in Ukraine’s external solvency.

In Ukraine’s case, her IMF Extended Fund Facility agreements (e.g. the 2023 program) tie disbursements to performance on fiscal and monetary targets, thereby linking external support to domestic restraint and signaling commitment to responsible policy.

When markets see that Ukraine is committed to a programme backed by US/Western institutions, speculative attacks are less likely.

Theoretical Constraints, Tensions, and Trade-Offs

Stabilising a currency via the above mixed scheme is not without inherent frictions and trade-offs. Below we highlight key constraints and tensions.

Reserve Erosion Risk and “Running Out of Gunpowder”

If speculative pressure is intense or sustained (e.g. capital flight, sudden stop), the central bank may be forced to continuously sell FX. Over time, reserves will dwindle. Once reserves are low, credibility unravels and a rapid depreciation may ensue.

Thus the system depends critically on aid arriving in time to replenish buffers before depletion.

Time Inconsistency and Moral Hazard

Because Ukraine cannot credibly commit to defending the currency indefinitely, there is a risk of time inconsistency: market participants may speculate on a devaluation if they expect that, under pressure, the authorities will abandon defense.

Moreover if firms or banks assume that the NBU will bail out foreign-currency exposures, they may take on excessive FX exposure—aggravating systemic risk.

Balance Sheet Mismatch and Currency Mismatches

Many firms and banks have liabilities denominated in foreign currency (USD, EUR) but revenues in UAH or local currency. A depreciation would amplify real debt burdens and potentially cause defaults or banking stress. This forces the central bank to be more conservative about devaluation.

Thus even moderate depreciation may generate systemic fallout, reducing policymakers’ flexibility.

Liquidity and Depth Constraints on Derivative Markets

Hedging markets (forwards, options, swaps) may be illiquid or segmented under stress, so not all exposures can be offloaded into derivatives. In crises, counterparties may withdraw or widen spreads, pushing pressure back onto the spot market.

Hence the buffer from hedging is imperfect, especially during turbulence.

Dependence and Conditionality of Foreign Aid

The entire “backing” modality depends on external financing being reliable, predictable and unconstrained by political cycles. Cuts or delays in US or Western support create severe vulnerability. Analysts already warn that declining donor aid is a looming risk for Ukraine’s macro stability. 

Thus while US-backed support buttresses the system, it also introduces dependency and sovereign risk.

Appreciation Risk and Misalignment

If the NBU only intervenes in one direction (say, only selling dollars), there is risk of overvaluation pressure in certain ranges, which can hurt competitiveness. A more balanced scheme would allow two-way interventions (i.e. buying dollars when UAH is unusually strong) to avoid currency misalignment. Some Ukrainian policy discussion refers to structuring interventions to allow flexibility in both directions, given adequate reserves. 

However, given Ukraine’s external constraints and war-related asymmetries, the tolerance for appreciation may be limited.

Evaluation: Strengths, Weaknesses, and Sustainability

Having laid out mechanics and tensions, we now assess the viability and robustness of the US-backed stabilisation approach.

Strengths

1. Shock absorption and smoothing of volatility

   
   

   The combination of FX reserves and intervention tools allows the NBU to blunt abrupt depreciation pressures, reducing disruptive volatility in trade, banking and pricing.

   
   

2. Credibility and confidence channel

   
   

   The knowledge that the US and Western allies stand behind Ukraine with financial support serves as a deterrent to speculative attacks. It raises the threshold for “attacks” and lowers risk premiums on UAH.

   
   

3. Risk sharing and flexibility

   
   

   External aid effectively shares some of the risk burden with international partners, enabling Ukraine to operate with a looser cushion than might otherwise be sustainable.

   
   

4. Policy discipline anchoring

   
   

   Tying disbursements to macro targets (via IMF or donor conditionality) helps reinforce fiscal and monetary restraint, essential for preventing inflation runs or credibility collapse.

Weaknesses and Risk Factors

1. Aid volatility and political risk

   
   

   The biggest vulnerability is that US/Western aid is subject to political cycles, oversight, shifting priorities, or fatigue. If aid is abruptly reduced, the entire system can be destabilised.

   
   

2. Finite reserve buffers

   
   

   Reserves, even if sizable, are not inexhaustible. Large shocks (capital flight, global dollar stress) can overwhelm them.

   
   

3. Asymmetric pressures under war

   
   

   In wartime, Ukraine is more exposed to asymmetric external shocks (commodity price swings, sudden donor shortfalls, supply chain disruptions). These asymmetries make currency defence more fragile.

   
   

4. Structural currency mismatch in the domestic economy

   
   

   Because many domestic entities are exposed to foreign currency debt, even limited depreciation can generate banking or corporate crises, constraining how far the exchange rate can move.

   
   

5. Anchoring fragility and self-fulfilling risk

   
   

   If market participants sense a weakening in backing—say, a delay in U.S. disbursements—they may preemptively devalue the currency, generating a rapid cycle of capital flight.

   
   

6. Absence of a mechanical peg

   
   

   The fact that Ukraine does not commit to a fixed peg to the U.S. dollar means that the regime is inherently discretionary. Flexibility is useful, but it also implies that under stress, the regime may retract.

Sustainability and Future Challenges

For the US-backed stabilisation to remain viable long term, several conditions must hold:

• Continued donor commitment: The US and Western allies must sustain sufficiently large, predictable transfers (grants, loans, guarantees) over medium to long horizons.

  
  

• Macro policy consistency: Ukraine must maintain discipline in fiscal and monetary policy to avoid inflation expectations unraveling and speculative attacks.

  
  

• Deepening financial markets: Enhancing depth and liquidity in FX-derivative markets helps absorb shocks more smoothly.

  
  

• Structural rebuilding: Growth, export diversification, stronger tax base, improved governance and institutional reforms reduce reliance on external support over time.

  
  

• Crisis contingency planning: Ukraine should develop fall-back mechanisms, such as temporary capital controls, FX auction systems, or more flexible exchange rate bands, to manage extreme cases.

In the longer run, the aim would be to shift toward a self-sustaining regime, gradually reducing dependence on donor backing. But given the wartime and geopolitical constraints, that transition may be protracted.

Conclusion

In refined academic terms, the stability of the hryvnia relative to Western currencies is undergirded not by a literal US-Treasury–backed peg, but by a hybrid stabilisation regime comprising: central bank FX interventions based on reserves, supportive forward/hedging markets, prudential constraints, and—crucially—external financial backing from the United States and allied institutions. The external support plays the dual role of reserve reinforcement and credibility anchor.

This regime works insofar as the scale and reliability of external support remain sufficient relative to speculative pressures and Ukraine’s external deficits. But it is fragile: reserve depletion, aid volatility, balance sheet mismatches and institutional slippages all pose serious risks.