Dollar Loan or Euro Funding? Compare Cross-Currency Basis, Fees and Break-Even Rates
Compare two ways to fund $10 million for 90 days. Calculate the break-even forward, see how fees reverse an apparent saving, and distinguish executable funding from a screen quote.
A 3% euro loan can fund dollars at a higher cost than a 5% dollar loan. The missing part of the comparison is the price of buying back euros to repay the original borrowing, including interest. Once that exchange is locked, the cheaper-looking interest rate may produce the larger dollar bill.
For a treasury comparing quotes, the task is to put the same usable dollar amount, dates and full repayments on one basis. The $10 million example below calculates that cost, identifies the break-even forward, and shows how a fee can turn an apparent saving into a loss of price advantage. Cross-currency basis explains the pricing; it does not replace the cash-flow comparison.

Conceptual illustration of currency funding, not observed market prices or an exchange-rate forecast.
A $10 million funding need, traced to maturity
Suppose an institution needs $10 million for 90 days. It can borrow euros, sell them for dollars today and simultaneously agree to buy back its euro repayment forward. All inputs below are hypothetical, not current market rates. Assume matching value dates, comparable borrowing terms, simple annual interest and a 90/360 year fraction. Bid–ask spreads, fees and collateral costs are excluded from this calculation, not from real-world decisions.
| Input | Assumption |
|---|---|
| Spot S, dollars per euro | 1.1000 |
| 90-day forward F, dollars per euro | Approximately 1.10682382 |
| Euro borrowing rate | 3% a year |
| Comparable direct dollar borrowing rate | 5% a year |
| Year fraction T | 90/360 = 0.25 |
Borrowing €9,090,909.09 and selling it at 1.1000 produces $10 million. After 90 days, the euro principal and interest total €9,159,090.91. That entire repayment—not merely the original principal—must be covered by the forward purchase if the currency amount due is to be locked.
Buying the euro repayment at the agreed forward requires $10,137,500. The $137,500 cost over a quarter implies a 5.5% annual dollar rate. Borrowing dollars directly at 5% would instead require $10,125,000 at maturity. The difference is $12,500. Amounts use the unrounded forward rate; the displayed quote is rounded.
Dollar funding premium = 5.5% − 5% = 0.5 percentage point, or 50 basis points. The cash check is $10 million × 0.005 × 0.25 = $12,500. Quoting the spread annually does not mean paying a full year's premium on a three-month loan.
Forward points already contain the interest differential
With S and F both expressed as dollars per euro, the implied dollar rate is:
[(F/S) × (1 + euro rate × T) − 1] / T
Under the same simplified assumptions, the no-basis forward is:
S × (1 + dollar rate × T) / (1 + euro rate × T)
At dollar and euro rates of 5% and 3%, respectively, that forward is approximately 1.10545906. It exceeds spot even without an additional funding premium. The illustrative traded forward of 1.10682382 is higher still, pushing the implied dollar rate to 5.5%.
Positive forward points therefore do not, by themselves, establish dollar scarcity. Nor are they a prediction that the euro must appreciate. First separate the points justified by matched interest rates from the residual funding difference.
How the same pricing can produce opposite signs
The positive 50-basis-point number expresses the extra cost on the dollar side. A convention that adjusts the euro interest leg instead can produce a negative number. To illustrate the sign—not to price a real multi-period swap—write:
F/S = (1 + dollar rate × T) / [1 + (euro rate + b) × T]
Using the same inputs gives b of approximately minus 49.69 basis points. A positive 50-basis-point dollar premium and a negative 49.69-basis-point euro-leg adjustment can describe the same relative pricing.
Even this simple case is not an exact sign flip. Actual cross-currency swaps require their payment schedules, compounding, discount curves, collateral terms and possible notional resets. Before interpreting a chart, identify the spread-bearing leg and translate the quote into a sentence about who pays what to obtain which currency.
A short-end spike may be about dates
A one-week contract spanning quarter-end need not face the same funding conditions as a one-week contract that does not. An expensive settlement day can have a large annualised effect when allocated across a short interval.
Compare actual value and maturity dates, holidays, quote sides and reference rates—not just tenor labels. A one-year basis quote describes a contract's maturity; it does not mean a deviation has already persisted for a year. A changed benchmark or settlement window can also break a seemingly continuous chart comparison.
A move isolated to one quarter-end maturity is weak evidence of a general dollar shortage. A broad rise in executable dollar funding costs across currencies and maturities, supported by money-market or credit evidence, makes a funding-stress interpretation more persuasive. This is corroboration, not a universal crisis threshold.
The break-even forward: when a cheaper quote stops saving money
To compare a new quote, keep the same $10 million of net usable dollars, dates, 90-day term and borrowing rates, but use a separate hypothetical forward of 1.1050 dollars per euro. Buying back the euro principal and interest now costs $10,120,795.45, versus $10,125,000 on the direct dollar loan. The apparent saving is $4,204.55.
That is also the maximum additional maturity-date fee the synthetic route can absorb relative to the direct loan before losing its advantage. If only the synthetic route carries a $6,000 fee payable at maturity, its total payment becomes $10,126,795.45: $1,795.45 more than borrowing dollars directly. Neither loan's initial net dollar proceeds have changed in this example.
For another quote, let D be the required net dollar proceeds, cDirect the direct loan's additional costs, and cSynthetic the synthetic route's additional costs. Both cost amounts must be expressed in dollars payable at the same maturity date. Equating the two total payments gives:
F* = S × [D × (1 + rUSD × T) + cDirect − cSynthetic] / [D × (1 + rEUR × T)].
Without fees, the break-even forward is 1.10545906. With the $6,000 fee only on the synthetic route, it falls to 1.10480397. For this quote direction and cash-flow structure, an executable F below the relevant threshold lowers the synthetic repayment; a higher F raises it. The calculation compares costs under specified conditions, not the suitability of two otherwise different credit arrangements.
Use the executable spot bid when selling euros and the executable forward offer when buying them back. A spread already included in those prices must not be charged twice. Rates and quotes must also be available together: yesterday's borrowing rate and today's forward can produce a saving that was never executable.
An upfront deduction requires a different cash-flow treatment. Restore the same net usable dollars by allowing for additional borrowing and its interest, or value the outflows consistently at a common date. Refundable collateral principal is not itself a fee, although funding that collateral and meeting potential margin calls can determine whether the cheaper route is usable at all. A lower maturity payment cannot substitute for a committed credit line or enough liquidity between now and maturity.
Three swaps that should not be confused
An FX swap exchanges currencies on a near date and reverses that exchange on a far date at an agreed rate. Its financing economics are embedded in those exchanges and the associated funding arrangements. Forward points are not simply a standalone service fee.
A cross-currency swap generally runs longer and also exchanges periodic interest payments. A basis spread adjusts one interest leg; payment schedules, collateral and any notional resets matter. A central-bank liquidity swap arrangement is a separate policy facility, not the same contract between private counterparties.
Start with a deliberately explicit measure: the dollar rate implied by funding through an FX transaction minus a comparable direct dollar funding rate. Call that the dollar funding premium. Positive means more expensive dollars under this definition—not under every convention used to quote a cross-currency swap.
A narrower basis does not rewrite an existing contract
Once the example's funding and forward purchase are locked, unchanged contractual terms still require $10,137,500 at maturity. A subsequent fall in the market premium from 50 to 20 basis points does not automatically reprice that transaction.
For a new, otherwise identical $10 million, 90-day transaction, a 20-basis-point premium would add $5,000 rather than $12,500. The $7,500 saving belongs to the new funding comparison or a future rollover opportunity. It is not an automatically realised gain on the old deal.
The old contract's mark-to-market value can change, and an early unwind may generate a payment or cost. Those are separate from its agreed maturity cash flows. If underlying interest rates also move, a narrower basis alone cannot establish that the new all-in funding rate has fallen.
An attractive screen price is not the same as access to cash
Textbook deviations are not freely available arbitrage profits. Borrowing and lending rates differ. Spreads, credit limits, collateral and balance-sheet usage affect whether either route can be executed. A policy rate or an overnight-indexed swap rate is an analytical reference, not an unconditional loan offer to every institution.
Ask whether the quote is firm for the required size, whether its bid–ask spread is normal and whether the counterparty will actually extend credit. Better pricing for a large bank does not prove restored access for smaller borrowers. Trading volume alone has no fixed interpretation as evidence of recovery.
Finally, similar dollar funding demand can arise from hedging a dollar bond portfolio, meeting an invoice or building precautionary liquidity. Those uses need not imply the same spot-market direction. Read basis first as a dated funding cost with specific contractual and access conditions; only then consider how that cost may transmit to other markets.


