Is an ADR Discount Really Tradable? Share Ratios, FX and Conversion Costs

An ADR shown at a discount to its home-market shares is not automatically a cheaper version of the same trade. The displayed prices may represent different numbers of shares, different currencies and different moments in time. Even after those differences are corrected, the cost of converting and delivering the securities can exceed the apparent gap.

The useful question is whether a specific route leaves anything after buying one side, selling the other and completing the required delivery. That calculation has two directions, and each uses different bid and ask prices. A worked example shows how a headline discount of 0.65% can leave both routes with a negative result.

Start with the number of ordinary shares represented by one ADS

Strictly, an American Depositary Receipt is the certificate evidencing American Depositary Shares, or ADSs. Market commentary often uses ADR and ADS interchangeably. We will calculate per traded ADS, because the relevant ratio is the number of ordinary shares represented by that unit. It can be more than one, one, or a fraction; never assume a one-for-one relationship from the ticker alone.

For a rough comparison, let n be ordinary shares per ADS, P the local share price, and q the number of U.S. dollars per unit of local currency. The converted reference is n × P × q dollars per ADS. If the FX quote is instead local currency per dollar, the corresponding conversion uses division. Multiplying by an exchange rate without first writing its units can reverse the comparison.

Check that the two instruments represent the same share class and distribution entitlement, with any ratio changes or corporate actions incorporated. Having the same issuer does not mean that two securities are interchangeable. Dollar trading also does not remove the underlying currency exposure; it merely changes the currency in which the ADS is quoted.

A complete set of hypothetical inputs

Assume a hypothetical ADS representing two ordinary shares. LC is a fictional local currency. The quotes below are assumed to be contemporaneous, available in sufficient size, and usable by the same participant. Both conversion directions and the necessary securities borrowing are assumed available; cash value dates match or their funding gaps are covered. These are analytical conditions, not terms taken from an actual deposit agreement.

A sale of ordinary shares receives their bid. Selling those LC proceeds receives the FX bid. Buying ordinary shares requires their ask, and purchasing the LC to pay for them costs the FX ask. The same directional discipline applies when choosing executable bid and ask rates for a currency conversion.

The share midpoint is 80 LC and the FX midpoint is 0.125 USD per LC, giving 2 × 80 × 0.125 = 20 dollars per ADS. The ADS midpoint of 19.87 therefore shows a 0.65% discount. Even its 19.90 purchase ask appears 0.50% below that reference. Neither percentage includes a complete conversion route.

Add the following hypothetical costs per ADS, beyond the spreads already embedded in the stock and FX quotes. No dividends, ratio changes or additional taxes occur in this example. Any applicable tax or other unlisted charge must be added for a real transaction; its absence here is not an exemption.

To show how delays affect the result, define the carrying allowance as 20 dollars × an assumed combined annual rate of 18% × 5 calendar days/360 = 0.05 dollars. The rate, charging base and five-calendar-day period are invented calculation inputs, not market estimates or a promised conversion time. Actual funding and stock-loan charges can have different bases, currencies and accrual periods. Nor does a cost allowance establish that the required collateral and cash are available.

Two conversion routes produce two different break-even tests

When the ADS looks cheap, the matching route buys one ADS and, at the same time, sells two ordinary shares, using a stock loan if the participant does not own deliverable shares. The FX trade must also be fixed for the required value date; if local short-sale proceeds are restricted, a separate funding arrangement must cover that delivery. Cancelling the ADS then provides the ordinary shares needed for delivery or to repay the loan, subject to the actual arrangements.

The ordinary-share sale produces 2 × 79.80 × 0.1248 = 19.91808 dollars. After the cancellation-route costs of 0.12, the comparison threshold is 19.79808. Subtract the actual ADS purchase ask: 19.79808 − 19.90 = −0.10192 dollars per ADS. The apparent discount has not paid for the route.

The reverse route buys two ordinary shares and, at the same time, sells one ADS at the stated bid, using an ADS loan if needed. After the shares are deposited and an ADS is issued, that ADS completes delivery or repays the loan. The FX purchase is also fixed for the required value date. Purchasing the LC and shares costs 2 × 80.20 × 0.1252 = 20.08208 dollars. Add the issuance-route allowance of 0.14 to obtain 20.22208. The actual ADS sale bid of 19.84 leaves 19.84 − 20.22208 = −0.38208.

In symbols, the cancellation route has a positive modeled balance only if A_ask < n × P_bid × q_bid − C_cancel. The issuance route requires A_bid > n × P_ask × q_ask + C_issue. A is the ADS dollar quote; each C is the additional route cost in dollars per ADS. These are directional break-even thresholds, not a fair-value interval into which an ADS midpoint must fit.

A small positive balance is still conditional

Hold the local-share, FX and cost assumptions fixed, and change only the ADS quote in three independent scenarios. The resulting balances are dollar amounts per ADS, not percentages of return. The number of decimal places preserves the arithmetic; it does not imply that every market or fee schedule settles at that precision.

At a 19.76 ADS ask, the cancellation route has a modeled surplus of 0.03808. Suppose conversion takes four additional calendar days. On the example’s assumed charging basis, that adds 20 × 18% × 4/360 = 0.04 dollars, changing the balance to −0.00192. A delay can overturn the sign before considering an adverse fill or an extra transfer charge.

These balances assume that all price-dependent legs can be executed on the stated terms and that the securities can ultimately complete the route. A positive cell does not establish either fact. If one leg fills and another does not, the result is an open position; a subsequent exit price may differ materially. Short-sale proceeds should not be treated as freely available funding without checking the account’s margin and cash arrangements.

An old local close cannot be upgraded into a live quote by changing the FX rate

Consider a separate timing example. At t0, the ordinary share closed at 80 LC and the FX midpoint was 0.125, giving an ADS reference of 20. At t1, while the local market is closed, an ADS reference price is 19.90. Comparing it with 20 displays a 0.50% discount. This is a reference-price comparison, not an executable trade.

Updating only the exchange rate reverses the apparent sign, but the local share price is still stale. There is no live bid at 80 to use in a sale. The next opening price is unknown, so neither row proves a realizable spread or identifies which market is “wrong”. A useful comparison records quote timestamps, open-market status, depth, currency and settlement date together.

Conversion access and borrowing must be verified before applying the formulas

The SEC’s ADR investor material directs investors to the deposit agreement and its fees, including the Form F-6 documentation. A broker that allows secondary-market ADS trading may still require separate arrangements to process issuance, cancellation and delivery to the local account. An exchange listing alone is not confirmation that a particular customer can use both routes.

Actual filings on EDGAR describe documentation, fees, taxes and applicable-law conditions, as well as possible temporary delays. Other issuer disclosures explicitly identify time-zone and conversion delays that can prevent the expected sale or settlement. These are reasons to check the relevant program and current service arrangements, not evidence that every depositary uses the same deadline or has an unrestricted right to block withdrawals.

The borrowed instrument also differs by route: the cheap-ADS route may need ordinary shares, whereas the reverse route may need ADSs. Confirm availability, loan charges, collateral, term and recall or replacement provisions for the correct security. If the route spans a distribution, any payment owed to the lender and the entitlement on the purchased instrument must be matched. Buying first and waiting to convert before selling, without a secured sale leg, leaves price and currency exposure during the wait.

What would make the comparison meaningful?

1. Verify the current ADS-to-share ratio, share class and corporate-action treatment from the program documents.
2. Obtain contemporaneous executable stock, ADS and FX quotes for the intended size, with their value dates and cash requirements.
3. Confirm the required issuance or cancellation route, receiving account and securities loan before assuming that delivery can be completed.
4. Itemize directional costs, taxes and time-dependent carrying charges without counting quoted spreads twice.
5. Recalculate after a delay, partial fill, borrowing change or entitlement mismatch; reject the original comparison when its inputs no longer hold.

A price gap becomes informative only after the units, transaction direction and delivery path agree. Until then, an ADR discount is a description of selected screen prices, not a demonstrated opportunity to lock in a profit.