Currency

Before currency becomes trading-system reference data, it is a narrowing chain of three related but distinct concepts. Money is the broadest: any generally-accepted, verifiable record of value, defined by the four functions it performs rather than by its physical form. Kinds of Money surveys the historical forms that convention has taken – commodity, fiat, bank money, and the modern, deliberately ambiguous case of cryptocurrency. Currency itself narrows money down to a system of money in common use within an area of circulation, standardised by ISO 4217 or left outside that standard entirely, and possessing its own lifecycle of creation, circulation, and eventual withdrawal. Cash narrows the chain a final step, to the most liquid instances of a currency, and brings with it the broader vocabulary of assets, liquidity, and cash flow that cash sits within.

A single position is never described by only one currency once a booking, ledger, and risk system is layered on top of the conceptual foundation above. Functional currency is the ledger's own accounting currency, dictated by a book's legal jurisdiction rather than freely chosen. Presentation currency is a purely presentational, live-spot conversion with no risk consequence of its own, best kept equal to aggregation currency for consistency. Transaction currency and denominated currency describe the currency in which a deal's own cash flows or results are properly expressed before any cross-currency comparison is attempted. Aggregation currency is what a risk engine converts every amount into so that deals with different denominated currencies become comparable – a conversion that, unlike presentation currency's, generates real risk rather than merely displaying a number differently. Two narrower roles round out the set: settlement currency governs a trade's settlement-day calendar and cash-settlement payment, and premium currency governs the currency an option's premium is paid in – itself the denominated currency an option resolves to, since no single transactional currency otherwise applies. Book currencies sits apart from the rest of this list: rather than describing how a position is expressed, it constrains which currencies a book may hold an instrument in at all.

A system carrying this many simultaneous currency roles needs mechanisms that keep them converted and reconciled against one another rather than silently drifting apart. Sweep documents the two distinct sweep mechanisms: a periodic, front/middle-office spot sweep crystallising non-presentation-currency profit, and a daily, automated, accounting-layer ledger sweep translating transactional balances into functional currency. FX Spot Revaluation Types breaks that ledger-sweep translation down further into the three accounting treatments settled and unsettled FX require – Balance Sheet, Position Account, and Forward Position reval. Closing Rates Screen is where the automated End-of-Day rate these mechanisms depend on meets human review, letting a stale or misquoted rate be caught and, if needed, overridden before it propagates into every downstream EOD figure. Beyond the currency cluster itself, CRM risk: recentering and artefacts and Book and the ledger work through the fuller consequences of aggregation currency and functional currency respectively, at the level of an entire cross-rates matrix and an entire accounting hierarchy.