Market-On-Close Orders (MOC): What Aussie Investors Need to Know in 2025

For Australian investors and traders navigating the fast-evolving world of equities in 2025, execution timing can make a dramatic difference to outcomes. One advanced tool gaining attention on the ASX is the Market-On-Close (MOC) order. Whether you’re a seasoned trader or a curious retail investor, understanding how MOC orders work—and when to use them—can be a game-changer in your trading strategy.

What is a Market-On-Close Order?

A Market-On-Close (MOC) order is an instruction to buy or sell a security as close as possible to the closing price of the trading session. Rather than executing immediately or at a specified price, MOC orders are queued to be filled during the closing auction, typically at the official closing price set by the exchange.

• Execution timing: MOC orders are executed during the market’s closing auction, not during continuous trading.

• Price certainty: The final trade price is the official closing price, providing transparency and consistency—key for fund managers and index trackers.

• ASX specifics: On the ASX, the Closing Single Price Auction (CSPA) determines the final price, and MOC orders must be submitted before the market’s closing auction window.

Why MOC Orders Are Gaining Popularity in 2025

The ASX has seen a significant uptick in MOC order usage, spurred by both regulatory updates and increased interest from institutional investors. Several factors are driving this trend:

• Index rebalancing: Fund managers frequently use MOC orders to match the closing price for benchmark tracking and compliance with index methodologies.

• Liquidity focus: The closing auction typically concentrates liquidity, reducing the risk of market impact for larger trades.

• 2025 ASX enhancements: This year, the ASX rolled out improved closing auction mechanisms, including tighter rules on MOC order submission cut-off times and increased transparency on auction volume and indicative prices. These updates have made MOC orders more attractive and reliable.

• Retail adoption: More online brokers now offer MOC functionality, making it accessible to everyday investors who want to avoid price swings near the close.

Example: A super fund tracking the S&P/ASX 200 index may use MOC orders to rebalance its portfolio at month-end, ensuring that its trades align with the official closing prices used by the index.

Best Practices and Risks for Aussie Investors

While MOC orders can be powerful, they’re not without pitfalls. Here’s how to make the most of them in 2025:

• Know the cut-off: The ASX closing auction typically starts at 4:00 pm Sydney time, with MOC order submissions closing shortly beforehand. Missing the window means your order won’t be included in the day’s closing auction.

• Understand liquidity: For blue-chip stocks, closing auction liquidity is deep. For smaller-cap shares, volumes may be thin, and prices can be volatile.

• Stay informed on policy: The 2025 ASX policy update introduced enhanced post-trade transparency and revised auction rules. For example, sudden surges in closing auction volume now trigger a brief extension to prevent price manipulation.

• Be aware of potential price swings: While MOC orders aim for the official closing price, late-session news or large order imbalances can cause unexpected closing price moves.

Tip: If you’re a retail investor, check with your broker about MOC order availability and associated cut-off times, as these can vary between platforms.

How MOC Orders Fit Into a Broader Trading Strategy

Market-On-Close orders are not just a technical curiosity—they can be a strategic tool for anyone needing to trade at the market’s close. Here’s how they’re commonly used in 2025:

• Passive investing: Index funds and ETFs use MOC orders for rebalancing and cash flow management.

• Event-driven trading: Traders may use MOC orders to capture price moves following after-market news or ASX index changes.

• Tax considerations: End-of-day pricing can be relevant for capital gains tax event timing, especially near the financial year-end.

With the ASX’s recent focus on transparency and fairer closing auctions, MOC orders are likely to remain a preferred tool for both institutional and retail investors in the years ahead.