CSL shares suffer their biggest one-day crash ever! What just went wrong?

CSL Ltd (ASX: CSL) shares are being hammered on Monday after the healthcare giant released another painful update to the market.

At the time of writing, the CSL share price is down 20.60% to $95.19.

That marks the company’s biggest one-day loss on record and adds to what has already been a brutal fall for shareholders. CSL shares are now down 45% in 2026 and more than 60% over the past year.

Here’s why investors are rushing for the exits.

Guidance gets cut again

According to the release, CSL has lowered its FY26 outlook after interim CEO Gordon Naylor completed his 90-day review.

The company now expects FY26 revenue of about US$15.2 billion on a constant currency basis. It also expects NPATA of about US$3.1 billion, excluding restructuring costs and impairments.

That is a step down from FY25, when CSL reported revenue of US$15.6 billion and profit of US$3.3 billion on a constant currency basis.

The update follows a difficult first half and another reset in expectations. CSL said its growth initiatives are working, but the financial benefits will take longer than previously expected.

What has gone wrong?

There are a few moving parts behind the downgrade.

In US immunoglobulin, CSL said demand is still growing at mid to high single digits. However, the normalisation of channel inventory is expected to hit revenue by about US$300 million.

In China, albumin volumes have stabilised, and CSL’s market share has expanded. But market value has declined, creating an expected revenue impact of about US$200 million.

Other pressures include the Middle East conflict, slower Hemgenix growth, and competition in iron. Together, these are expected to have a revenue impact of about US$150 million.

The better news is that CSL Behring is still expected to grow revenue in the second half. CSL Seqirus is also expected to perform moderately better than previously expected.

More impairments to come

The other big number in today’s release is the impairment charge.

CSL expects to recognise about US$5 billion of additional non-cash, pre-tax impairments across FY26 and FY27. That comes on top of the US$1.5 billion already recognised in its first-half result.

The impairments include CSL Vifor’s intangible assets, including its product portfolio. They also include selected property, plant, and equipment.

Foolish Takeaway

CSL remains a global healthcare heavyweight, but the market has lost patience with repeated downgrades, write-downs, and execution issues.

The company is working on portfolio growth, operational savings, and capital discipline. Management is targeting transformation savings of US$500 million to US$550 million a year by FY28.

But after such a large share price fall, investors will want proof in the numbers. Until earnings stabilise, CSL shares may struggle to win back confidence.

The post CSL shares suffer their biggest one-day crash ever! What just went wrong? appeared first on The Motley Fool Australia.

More reading

• CSL cuts FY26 guidance, flags $5bn in impairments
• Why I’d buy CSL shares at their 52-week low
• Is this ASX healthcare share a buy for its 6.2% dividend yield?
• 3 compelling reasons to buy CSL shares today
• Money to invest? I’d follow Warren Buffett to get rich

Motley Fool contributor Aaron Teboneras has no position in any of the stocks mentioned. The Motley Fool Australia’s parent company Motley Fool Holdings Inc. has positions in and has recommended CSL. The Motley Fool Australia has recommended CSL. The Motley Fool has a disclosure policy. This article contains general investment advice only (under AFSL 400691). Authorised by Scott Phillips.