Onshore vs Offshore Currency Markets
Some currencies trade at two different rates at once — one inside the country's borders under its own rules, one outside them, freely — and the gap between the two tells you something the official rate hides.
Prerequisites: Currency Pegs and Managed Floats
The Chinese yuan trades under two different tickers: CNY, the rate inside mainland China, subject to the People's Bank of China's controls and daily trading band, and CNH, the rate for yuan traded offshore — mostly in Hong Kong — outside those controls. The same underlying currency, two prices, existing side by side. This split isn't unique to China; several currencies subject to capital controls develop a similar onshore/offshore divide.
Why a currency ends up with two prices
When a government restricts who can hold, convert, or move its currency across borders, it effectively creates two separate liquidity pools: the tightly regulated onshore market, where the central bank can intervene directly and enforce rules on capital flows, and a lightly regulated offshore market that develops naturally wherever foreign banks and investors need to trade the currency without being subject to those domestic restrictions. Because the offshore market isn't directly controlled by the home central bank, its exchange rate is freer to move with market sentiment and expectations, while the onshore rate stays anchored closer to whatever band or fixing the central bank targets.
The gap between the two rates is informative: a persistent offshore discount (offshore currency trading cheaper than onshore) signals the market expects the currency to weaken and that capital controls are actively suppressing that depreciation from showing up onshore. A widening gap during periods of stress is often read as a signal of capital flight pressure the onshore rate isn't allowed to reflect.
What this means in practice
Traders and investors watch the onshore-offshore spread as a real-time gauge of underlying currency pressure that the official onshore rate, constrained by policy, is hiding. Offshore markets also let global investors and companies hedge or speculate on a controlled currency's moves without needing direct access to the restricted onshore market — which is precisely why authorities sometimes intervene in the offshore market too (as China's central bank has done in the CNH market) when the offshore rate moves in a direction officials find undesirable, since a persistently wide gap can itself fuel further speculation about a coming devaluation.
Currencies under capital controls, like the Chinese yuan, can trade at two different rates simultaneously — a tightly managed onshore rate and a freer offshore rate. The gap between them is a real-time signal of underlying depreciation pressure that the controlled onshore rate isn't allowed to show.
Related concepts
Practice in interviews
Further reading
- BIS Quarterly Review, articles on offshore renminbi (CNH) market development