The FX execution map for a family-office book, after the 2025 BIS Triennial

On 30 September 2025 the BIS published the preliminary results of the 14th Triennial Central Bank Survey of foreign exchange and OTC derivatives markets. The final FX turnover data, and the settlement data, came out with the BIS Quarterly Review in June 2026. The April 2025 reading is the largest on record, and the one that is reshaping how a multi-currency family-office book is run.

A USD 9.6 trillion-a-day market is now done almost entirely between professionals. The market has grown 28% in three years. The US dollar was on one side of 89.2% of every trade. The euro is on 28.9%, the yen on 16.8%, sterling on 10.2%, the renminbi on 8.5%, the Swiss franc on 6.4%. The top four financial centres (the United Kingdom, the United States, Singapore, Hong Kong) intermediate 75% of total trading (BIS, Triennial Central Bank Survey, 30 September 2025; final results in the BIS Quarterly Review, June 2026).

The number that frames the rest of the brief is 5%. In April 2025, non-financial customers (corporates, governments, family offices and other end users) accounted for 5% of global FX trading, down from 13% in 2010. A market that has grown by a factor of 2.4 in fifteen years is now also a market in which the family-office book is, by construction, a small share of the order book.

The framework the desk uses to write an FX execution policy in 2026 is built on those three lines: the size, the geography and the counterparty mix. None of them is a view on the dollar, the euro or the rand. All of them sit underneath the corridor policy the principal signs.

In April 2010 global FX turnover was USD 3.97 trillion per day, on a net-net basis that corrects for both local and cross-border inter-dealer double-counting. By April 2013 it was USD 5.36 trillion, by April 2016 USD 5.07 trillion (the only decline in the series since 2001), by April 2019 USD 6.59 trillion, by April 2022 USD 7.51 trillion, and by April 2025 USD 9.60 trillion (BIS Triennial Central Bank Survey, 2010 through 2025 editions).

The composition has shifted as much as the size. In April 2022, FX swaps made up 51% of global turnover, spot 28%, outright forwards 15%, options 4% and currency swaps 2%. In April 2025 the share of FX swaps had fallen to 42%, while spot rose to 31% and outright forwards to 19%. Options more than doubled in share to 7%, as institutions paid for optionality in a more volatile regime. The 28% growth in total turnover since 2022 was led by spot (up 42%) and outright forwards (up 60%), the two instruments family offices use to lock in funding and convert liabilities.

A book that has to manage a USD/ZAR corridor, or a multi-currency liability stack, is sizing most of its execution against spot and forwards. The market in those two instruments grew by roughly USD 1.6 trillion a day in three years. The Triennial data is the right reference for sizing the corridor.

The other half of the structure is the counterparty. In April 2025 inter-dealer trading was 46% of global turnover, almost unchanged from 47% in 2022 but lower than the 51 to 55% range of 2010 to 2016. The category that has done all the growing is "other financial institutions", a broad bucket that includes non-reporting banks (24% of the total), institutional investors (13%), hedge funds and proprietary trading firms (8%), and official sector financial institutions.

Non-financial customers made up 5% of the total in 2025, down from 6% in 2022 and 7% in 2019. Inside that 5% the share attributable to family offices, smaller corporates and trust structures is a small fraction of a fraction. The practical reading is that a family office is now a price-taker in a market dominated by the cross-currents of prime-brokered hedge fund flow, the funding desks of the global banks and the trade-book hedging of large asset managers. The principal is not a counterparty. The principal is a customer.

The non-financial customer share series is the single most useful line in the Triennial for a family-office desk. In April 2010 the share was 13%, the lowest reading since 2001. By April 2013 it had fallen to 9%, the largest single drop on record. In 2016 it dropped to 7%, held at 7% in 2019, declined to 6% in 2022, and now sits at 5% in 2025 (BIS Triennial Central Bank Survey, 2010 through 2025 editions).

The arithmetic for a principal. A USD 1 million trade in April 2010 was roughly 2.5 parts per billion of the USD 3.97 trillion daily market, and around 1.9 parts per million of the non-financial customer flow. By April 2025 the same trade is about 1.0 part per billion of the USD 9.60 trillion daily market, and around 2.1 parts per million of the smaller non-financial customer flow. The total market has grown by a factor of 2.4. The non-financial customer pool in dollar terms is roughly the same as it was in 2010, between USD 480 and 516 billion per day. The principal's relative visibility to the broader market, and the relative weight of the principal's trade against the book of professional flow, has shrunk by the same factor of 2.4. Pricing on a single-dealer relationship reflects the dealer's view of the principal's relative bargaining position in a market that is, in aggregate, no longer structured around end users.

Three lines cover most of the work.

The first is the counterparty policy. A book that runs a single dealer for spot and forwards is, in 2025, paying for the convenience of a relationship with a price-spread the Triennial data says it does not need to pay. A written counterparty roster, with a minimum of two dealers for any currency pair representing more than 5% of the book, and a written multi-bank RFQ process for trades above a written threshold, is the version of the policy that holds against the market structure.

The second is the execution venue. The Triennial does not break out electronic against voice execution in the headline tables, but the regional FX committee surveys cited in the BIS commentary are explicit: voice trading remains the default for emerging market currency pairs and for trades above the USD 25 million equivalent mark. Electronic trading has become the default for the G3 pairs at smaller sizes. The policy is to write the venue rule against the size of the trade, not against the relationship.

The third is currency-pair discipline. The 2025 Triennial lists 41 currency pairs in regular reporting. Twenty-one of them have less than 1% share of global turnover. A family-office book that trades in three or four pairs is well within the deep, competitive part of the market. A book that reaches into thin pairs pays for the privilege in price-spread and in slippage, and the policy says not to do it without a written rationale.

The framework is written against the Triennial data, not against the dealer's pitch. The corridor policy the principal signs is the size of the book, the geographic distribution of the dealers and the counterparty mix. The trades are taken on the corridor edges, not on the prints.