I came across a payment service called Strike recently, and I’m interested in its use for international transactions.

From what I’ve read, I can send 100 USD from the US to someone in Argentina such that the receiver gets Argentine Peso (ARS). “Under the hood” there is a conversion that happens between fiat & bitcoin which I understand. However, given the volatility of bitcoin’s price, doesn’t this introduce issues if the bitcoin price changes during the transaction?

Transaction diagram:

USD —> BTC —lightning—> BTC —> ARS

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Does Strike somehow “lock in” the price of BTC after the first conversion from USD to BTC? Otherwise isn’t it possible for the price of BTC to drop before the transaction is complete which means you get unfavorable forex rate from USD to ARS?

Example illustrating my concern:

Exchange rate @ t=0

Forex rate

USD: 100

ARS: 19,937.59

Price of BTC

BTC: 1

USD: 20,586.70

ARS: 4,104,491.84

Exchange rate @ t=1

Forex rate

USD: 100

ARS: 19,937.59

Price of BTC is lower than @ t=0

BTC: 1

USD: 20,000

ARS: 3,987,518

USD —> BTC

At t = 0, 100 USD gets converted to BTC which yields 0.00485751 BTC.

BTC —> ARS

At t = 1, 0.00485751 BTC gets converted to ARS which yields 19,369.41 ARS.

Based on the Forex rate, the receiver should’ve gotten 19,937.59 ARS but because the price of bitcoin dropped during the transaction only 19,369.41 ARS was received.

I’m sure this part of the transaction BTC —lightning—> BTC —> ARS happens very quickly but is it consistently and reliably fast enough such that the effect of bitcoin’s volatility is negligible during the transaction?