GBP/USD: Cable

GBP/USD is the third most-traded currency pair, behind EUR/USD and USD/JPY, accounting for roughly 9-10% of daily FX turnover according to the BIS Triennial Survey. It is older than every other pair as a quoted market, the original transatlantic instrument, and the one most likely to make a careless position size hurt. This article walks the pair: the quote and the famous nickname, why it is structurally more volatile than EUR/USD, the macro drivers that move it, sessions, correlations, and the practical pattern.

What the quote says

GBP/USD = 1.2700 reads: one British pound is worth 1.2700 US dollars. The pound is the base; the dollar is the quote. A pip is the fourth decimal: a move from 1.2700 to 1.2701 is one pip. Pip value is the same as any dollar-quoted major: $10 per pip per standard lot, $1 per mini lot, $0.10 per micro.

The pound is unusual among majors in trading above the dollar in nominal terms. Historically the pound was worth several dollars; it has been below 2.00 since 2008 and visited 1.03 briefly in September 2022 during the gilt-market crisis. The high nominal value is a relic of the pound’s historical role as the world’s reserve currency before the dollar took over after the Second World War, not a statement about current value.

The “Cable” name

GBP/USD is Cable. The name dates from August 1858, when the first successful transatlantic telegraph cable was laid between Newfoundland and Ireland. The cable transmitted the sterling-dollar exchange rate between London and New York in minutes rather than the ten-plus days a ship had previously taken. Traders began referring to the quote being received on “the cable”, and the name stuck. It has survived the obsolescence of the telegraph, then the copper telephone cable, and now the fibre-optic systems that replaced both. The transatlantic quote is still the Cable in trading-floor language a hundred and sixty-plus years on. EUR/USD’s nickname (Fibre) is a modern joke on this lineage. (See EUR/USD: The Fibre.)

Why Cable matters

A few historical and structural reasons that GBP/USD punches above its volume weight:

• The City of London. The UK runs the world’s largest forex trading hub by location-based turnover, with London accounting for roughly 38% of daily global FX volume in the most recent BIS survey, ahead of New York. A meaningful share of all FX activity passes through London books, and GBP/USD is the home pair of that market.
• The historical reserve currency. Before the dollar’s post-1944 ascendancy, the pound was the world’s primary reserve currency. The legacy lives on in extensive UK government debt markets, deep gilt trading, and a sterling presence in global reserve allocations far larger than the UK’s economic weight would predict.
• DXY weight. GBP carries an 11.9% weight in DXY, the third largest after EUR and JPY. Cable matters to the dollar index in a way the actual size of the UK economy would not suggest.
• A free-floating, large, multi-policy currency. The pound is the most-traded floating currency outside the eurozone and the dollar bloc, with its own central bank and its own fiscal sovereignty. It produces idiosyncratic moves the other majors do not.

What drives Cable

GBP/USD has more moving parts than EUR/USD. The big drivers:

• Bank of England policy. The MPC meets eight times a year and publishes minutes alongside each decision. UK rate expectations shift the pound on Fed-relative grounds, with the BoE often out-of-step with the Fed on the cycle. The BoE-Fed real-yield spread is the cleanest single proxy for the Cable trend.
• UK inflation data. UK CPI prints monthly and has historically been a high-impact release. The UK has run through inflation regimes that diverged significantly from US and eurozone patterns (2022-2023 was the most recent example), producing sustained GBP-specific moves.
• UK growth data. Monthly GDP (the UK uniquely publishes a monthly GDP estimate), retail sales, the composite PMIs. The UK economy is smaller than the eurozone but its data is published more frequently, producing more frequent pound-specific signals.
• UK fiscal policy and politics. A pound trader’s job description includes paying close attention to UK political and fiscal news. The Liz Truss mini-budget episode of September 2022 produced a multi-standard-deviation collapse in sterling (and a separate crisis in the gilt market) within days. That episode was extreme but not unique. UK politics has a real, observable effect on the pound.
• Brexit and trade-relationship news. Less dominant than in 2016-2020 but still relevant. UK-EU trade developments register in GBP/USD.
• The DXY overlay. Like every USD pair, the Dollar Index is the macro background. A strong-DXY day pressures Cable; a weak-DXY day lifts it. GBP-specific news layers on top of, not instead of, the dollar story.

Why Cable is more volatile than EUR/USD

This is the defining practical fact about the pair and the one that catches beginners. GBP/USD typically prints a daily range of 80-150 pips versus EUR/USD’s 50-100 pips, and implied volatility usually trades 1-3 percentage points higher than EUR/USD on the same maturity.

The reasons are structural rather than coincidental:

• A smaller economy, freer-floating. The UK is around the size of the larger eurozone members but not the eurozone as a whole. Idiosyncratic UK shocks are not diluted across a 19-country bloc; they hit the pound directly.
• A more fiscally-active central government. UK fiscal policy changes more often, and more visibly, than US or eurozone fiscal policy. Each shift produces a sterling reaction.
• Higher event sensitivity. UK political surprises, Brexit-style shocks, and the historical gilt-market vulnerability all add episodic volatility that EUR/USD does not carry.
• Lower depth than EUR/USD. Around half the daily turnover at best. Per-unit slippage on a fast move is larger.

The implication for sizing is direct. A position size that is conservative in EUR/USD can be aggressive in Cable for the same dollar risk, because the same 30-pip stop has different probabilities of being touched in normal conditions on the two pairs. (See Risk Management Basics for the position-sizing framework.)

Sessions and liquidity

GBP/USD’s session pattern is similar to EUR/USD’s but with sharper asymmetries:

• Tokyo session (00:00-09:00 GMT). Notably quiet. Cable ranges are often very narrow during Asian hours; spreads can widen modestly. The pair is not what Asia trades.
• London open (08:00 GMT). Cable is the home-market pair of the London session, and the open is where most of the daily directional bias is established. UK data prints between 07:00 and 09:30 GMT, often into the open.
• London-New York overlap (13:00-17:00 GMT). The deepest window and the one where US data lands. Most of Cable’s daily range is typically made between 08:00 and 17:00 GMT.
• New York afternoon (17:00-22:00 GMT). Drops off as London closes. Late-day moves often lack follow-through and reverse the next morning.

The practical implication for retail traders is the same as for EUR/USD: trade the London open and the overlap, leave the rest. For Cable specifically, the London open is often the highest-quality session of the day; the overlap adds US data risk on top.

Correlations

Cable’s correlation web overlaps heavily with EUR/USD’s but is not identical:

• Strongly positive with EUR/USD. Both are USD pairs against major European currencies. The typical correlation runs +0.7 to +0.9, but it weakens when UK-specific or EU-specific news breaks the link.
• Strongly negative with DXY. The 11.9% weight is meaningful but smaller than EUR’s 57.6%. Cable’s DXY correlation is genuine but noisier.
• Positive with risk sentiment. GBP behaves as a moderate risk-on currency, less pronounced than AUD but more pronounced than CHF.
• Variable with EUR/GBP. EUR/GBP is itself derived from EUR/USD divided by GBP/USD, so the cross moves when EUR/USD and GBP/USD diverge. A Cable-trader watching EUR/GBP is reading the EUR-vs-GBP relative story directly.

A common pattern: when DXY is the dominant story of the day, EUR/USD and GBP/USD move together. When the story is UK-specific or EU-specific, they diverge sharply and EUR/GBP carries the information.

The honest tradability note

GBP/USD is liquid, volatile, and has more frequent setups than the calmer pairs, which makes it superficially attractive to active traders. It is also unusually punishing of poor risk discipline, because the same volatility that produces big moves produces big adverse excursions on normal-looking trades.

Realistic expectations:

• Higher headline volatility, similar long-run expected return. More movement does not mean more edge. The pair pays the same competitive market efficiency that EUR/USD does; it just pays it with more noise.
• Wider spreads than EUR/USD. Typical retail Cable spread is 1.0-1.5 pips vs EUR/USD’s 0.6-1.0. The cost-per-trip is modestly higher. (See Trading Costs Explained.)
• Event risk is real and frequent. UK CPI, MPC days, gilt-market episodes, political surprises. A meaningful share of Cable’s annual return is concentrated in a small number of event days. Holding through them without an event view is gambling on the event.
• The pair rewards size discipline more than most. A small oversize in Cable hurts more than the same oversize in EUR/USD, because the typical adverse-excursion is larger. Position sizing with a per-pair volatility adjustment (using ATR or implied volatility) is closer to correct than a fixed-pip stop across all pairs.

The takeaway

Cable is the original transatlantic pair, named for the 1858 telegraph cable that first carried sterling-dollar quotes across the Atlantic, and still one of the three most-traded pairs in the world. It is structurally more volatile than EUR/USD because of the UK’s specific fiscal, political, and inflation dynamics layered on top of the BoE-Fed policy story. It correlates strongly with EUR/USD in DXY-driven regimes and diverges sharply when the story is local. It is liquid enough to trade at retail with confidence and volatile enough to ruin a poorly-sized account quickly.

For the macro overlay, read The Dollar Index (DXY). For the companion pair, read EUR/USD: The Fibre. For the position-sizing discipline this pair really requires, read Risk Management Basics and Leverage and Margin Explained.