Exchange Rate Pass-Through / Pip Value Calculator implementation

Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

Record owner

Guth Instruments

Lifecycle

verified-clean

Evidence ID

t5-200

Effect

Computation or source lookup only

Input and validation requirements

A zero exchange rate causes an undefined division and must be rejected. The specification also leaves the pip-size regime for JPY pairs, the sign convention for position size, and conversion from the formula's quote-currency-dependent result into account currency insufficiently specified.

Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

{
  "inputs": {
    "currency_pair": "EUR/GBP",
    "account_currency": "USD",
    "position_size": 100000,
    "pip_size": 0.0001,
    "current_rate": 1.25,
    "current_rate_definition": "USD per GBP"
  },
  "expected_outputs": {
    "pip_value": 8
  },
  "working": "pip_value=(pip_size/exchange_rate)*position_size\n=(0.0001/1.25)*100000\n=0.00008*100000\n=8 USD per pip"
}

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche5/tranche5-results.json