Here is the part traders can miss when looking at the calendar. Markets do not move on economic data alone. They also move on participation, market depth and the amount of capital available on each side of the book.

When some of that participation disappears for a holiday, the market does not necessarily stop moving. The conditions underneath it change.

That matters on Friday 25 September 2026. The Shanghai Stock Exchange (SSE) and Shenzhen Stock Exchange (SZSE) will close for the Mid-Autumn Festival and reopen on Monday 28 September. Hong Kong Exchanges and Clearing (HKEX) also confirms that both Northbound and Southbound Stock Connect trading will be closed on 25 September.

There is an important distinction here. Hong Kong's general holiday for the day following the Mid-Autumn Festival falls on Saturday 26 September. So this is not a case of the entire region simply switching off at once. It is more interesting than that: parts of the normal liquidity network disappear while others stay active. And that is where things can get messy.

What changes when mainland markets close

To understand the holiday effect, start with market depth. The Bank for International Settlements (BIS) describes liquidity in trading through measures including bid-ask spreads, market depth and price impact. A deeper order book can generally absorb a larger transaction with a smaller price concession, all else being equal.

That does not mean every Mid-Autumn session will suddenly become volatile. It means some of the usual regional flow will be missing.

3 markets that could feel the difference

The impact will not be identical across every asset. Three markets are particularly relevant to the Asia-Pacific market outlook.

1. US dollar against offshore yuan (USD/CNH)

The distinction between the onshore yuan and offshore yuan matters here. USD/CNH trades in the offshore foreign exchange (FX) market, so mainland equity exchange closures do not mean the pair simply stops trading. But mainland closures can change the mix of regional participation and price discovery. That leaves global headlines, US monetary policy developments and China-related news capable of moving the offshore yuan while mainland cash markets are unavailable.

2. Hang Seng Index CFD

Hong Kong is a little more complicated. Friday 25 September is not a Hong Kong general holiday, but Northbound and Southbound Stock Connect will both be closed. That means one source of cross-border participation will be absent while the Hong Kong market itself remains active. For index-linked products such as the Hang Seng Index, that distinction can matter when interpreting a move during the session.

3. Australian dollar against US dollar (AUD/USD)

The Reserve Bank of Australia (RBA) identifies commodity prices, interest-rate differentials and global risk sentiment as important drivers of the Australian dollar. It also notes that the exchange rate can act as a buffer against global shocks. China matters within that broader picture because of Australia's trade and commodity exposure. So if China-related headlines arrive while mainland markets are closed, AUD/USD may still respond.

How market depth changes price impact

This is where the mechanics become useful. Market depth describes how much buying and selling interest is available at different prices. If more volume is sitting close to the current market price, a larger order may be absorbed without travelling very far through the book. If less volume is available, the same order may need to trade through several price levels before it is filled. That is price impact.

The holiday liquidity sweep, minus the conspiracy theory

Now we get to one of the more colourful phrases in trading language: the liquidity sweep.

Technical traders often watch previous session highs, lows and other visible price levels during the Asian session because orders can cluster around them. In thinner conditions, lower depth can mean orders clustered around session extremes have a larger price impact. That can produce a familiar-looking sequence: price trades quietly inside a range, moves beyond a visible high or low, orders are triggered, and then price reverses.

It is tempting to call that a "stop hunt". But the chart alone cannot tell you that somebody deliberately targeted retail stops. Sometimes the less dramatic explanation is enough: there was simply less depth available when the orders arrived. No villain required.

What thin holiday conditions can change

Holiday trading does not require a completely different rulebook, but the same setup can behave differently when participation changes.

Monitoring the holiday calendar alongside market hours, spreads and regional liquidity conditions can provide additional context around the technical setup already on the chart. Explore our foreign exchange CFDs and index CFDs for current product information, spreads and applicable market hours.