In afternoon trade on Monday, the S&P/ASX 200 Index (ASX: XJO) is on course to record a small decline. At the time of writing, the benchmark index is down by 0.2% to 8,586.2 points.
Four ASX shares that are falling more than most today are listed below. Here's why they are starting the week deep in the red:

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Antipa Minerals Ltd (ASX: AZY)
The Antipa Minerals share price is down 13% to 59.5 cents. This morning, this copper and gold explorer completed a strongly supported institutional placement to raise $40 million before costs. These funds were raised through the issue of approximately 66.7 million shares at a 12.4% discount of 60 cents per new share. The company's managing director, Roger Mason, commented: "This successful equity raise provides the financial flexibility and certainty required to unlock the full value of the Minyari Development."
Northern Star Resources Ltd (ASX: NST)
The Northern Star share price is down 7% to $17.08. Investors have been selling this gold miner's shares following the release of an operational update this morning. Northern Star revealed that its sales for FY 2025 will be at the low end of its revised guidance range. FY 2025 gold sold came in at 1,634k ounces, which compares to its revised guidance range of 1,630k ounces to 1,660k ounces. Looking ahead, management is guiding to 1,700k ounces to 1,850k ounces of gold sold in FY 2026. However, it warned that the first quarter of FY 2026 would be the softest and would be run-rating below guidance.
Pilbara Minerals Ltd (ASX: PLS)
The Pilbara Minerals share price is down over 4% to $1.45. This is despite there being no news out of the lithium miner today. However, it is worth noting that almost all lithium shares are falling today. A number of analysts believe that lithium prices are going to stay lower for longer due to increased supply out of Africa.
Synlait Milk Ltd (ASX: SM1)
The Synlait Milk share price is down 8% to 52 cents. Investors have been selling this dairy processor's shares after it announced the exit of its chief operating officer (COO), Paul Mallard. The company's CEO, Richard Wyeth, commented: "Paul has led multiple business functions and played a significant role in advancing the company's operational and strategic priorities. Under his leadership, the team has made notable progress optimising the North Island network and enhancing the overall value chain performance."