Why did CSL shares sink again in September?

CSL shares trailed the benchmark again in September. But why?

| More on:
A doctor shrugs and holds his hands out.

Image source: Getty Images

You’re reading a free article with opinions that may differ from The Motley Fool’s Premium Investing Services. Become a Motley Fool member today to get instant access to our top analyst recommendations, in-depth research, investing resources, and more. Learn More

Key points

  • CSL shares fell by 6.9% in September, underperforming the ASX 200's 1.4% decline, continuing their downward trend after August's significant drop.
  • The decline follows the planned demerger of its Seqirus segment, a major influenza vaccine business, aimed to be completed by FY 2026.
  • CSL's September announcement of a partnership with VarmX for a new blood coagulation treatment showed promise, yet investors remain cautious, with mixed analyst ratings on the stock.

CSL Ltd (ASX: CSL) shares underperformed the benchmark index again in September.

Shares in the S&P/ASX 200 Index (ASX: XJO) biotech stock closed out August trading for $212.89 each. When the closing bell sounded on 30 September, shares were changing hands for $198.20 apiece.

This saw CSL shares drop 6.9% over the month, trailing the 1.4% loss posted by the ASX 200 in September.

September's losses followed a horror month in August, a month that saw shares in the ASX 200 biotech stock crash by 21%. That sell-off looks to have been primarily spurred by the company's unexpected announcement that it will spin off one of its three business divisions.

Management said they aim to demerge the Seqirus segment – which counts as one of the world's largest influenza vaccine businesses – into a separate and "substantial ASX-listed entity". CSL aims to complete the demerger before the end of FY 2026.

Now, here's what ASX investors were looking at in September.

What happened with CSL shares in September?

The only price-sensitive announcement from the company was released on 16 September.

As the Motley Fool reported on the day, CSL revealed that it had entered into an agreement with Netherlands-based biotech company, VarmX. The partners will work on developing a new treatment to restore blood coagulation in patients taking an FXa inhibitor.

Yet CSL shares slipped 1.6% on the day, despite the company noting that more than 20 million people around the world currently take FXa inhibitors.

Investors may have concerns about the costs involved.

Under the agreement, CSL will fund VarmX's global Phase 3 trial, which will evaluate VMX-C001 in patients taking FXa inhibitors. CSL also said it will pay US$117 million to VarmX for an exclusive option to acquire the company once the Phase 3 data has been completed.

Commenting on the agreement that's intended to boost CSL shares longer term, CEO Paul McKenzie said on the day, "CSL has a long history of working in hematology and bleeding disorders and partnering with VarmX strengthens our strategic ambition to deliver enduring patient impact."

McKenzie added:

The preclinical and early clinical data are also very encouraging and led to the U.S Food and Drug Administration (FDA) granting Fast Track Designation, recognising VMX-C001's potential to address a critical unmet medical need.

Is the ASX 200 biotech stock now a good buy?

Following the recent big sell-down in CSL shares, a number of analysts have come out with renewed recommendations and price targets on the stock.

A fair number of experts remain leery of buying the ASX 200 biotech stock just yet, and they've issued hold recommendations.

There are also a few sell recommendations out there, but those look to be outweighed by the buy group.

In early September, both Morgans' Damien Nguyen and Family Financial Solutions' Jabin Hallihan came out with a bullish assessment for the company.

Hallihan noted, "Our 12-month analyst valuation is $291.31 as the long-term outlook remains intact."

That represents a potential upside of more than 31% from today's intraday CSL share price of $199.85.

Motley Fool contributor Bernd Struben 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.

More on Healthcare Shares

Researchers and doctors with futuristic 3d hologram overlay for body anatomy or dna in hospital clinic.
Healthcare Shares

Bell Potter names the best ASX healthcare shares to buy in 2026

Healthy returns could be on offer with these shares according to the broker.

Read more »

man cupping ear as if to listen closely, rumour, cochlear
Healthcare Shares

Why is everyone talking about Telix shares this week?

Let's see why this biotech stock has been on the move this week.

Read more »

Medical workers examine an xray or scan in a hospital laboratory.
Healthcare Shares

This ASX stock is going parabolic, and I think it's still a buy

4DMedical shares are up nearly 500% in 2025, but improving revenue visibility suggests the growth story may not be over.

Read more »

ecommerce asx shares represented by santa doing online shopping on laptop
Healthcare Shares

Looking for ideas before Christmas? These 2 ASX shares stand out to me

Two ASX shares at opposite ends of the market are catching my attention as the year draws to a close.

Read more »

A doctor or medical expert in COVID protection adjusts her glasses, indicating growth or strong share price movement in ASX medical, biotech and health companies
Opinions

Forget CSL shares, I'd buy this booming biotech stock instead

This ASX biotech stock has caught my eye this year.

Read more »

A medical researcher rests his forehead on his fist with a dejected look on his face while sitting behind a scientific microscope with another researcher's hand on his shoulder as if giving comfort.
Healthcare Shares

Telix Pharmaceuticals shares crash 58% from their peak: Buying opportunity or time to sell up?

The biopharmaceutical company's shares are tipped to soar next year.

Read more »

A male ASX investor sits cross-legged with a laptop computer in his lap with a slightly crazed, happy, excited look on his face while next to him a graphic of a rocket shoots upwards with graphics of stars scattered around it
Healthcare Shares

Up 10x since July, could this hot ASX stock be the next Droneshield?

Investors chase asymmetric upside and 4DMedical is one of the ASX's hottest stocks right now.

Read more »

A couple smile as they look at a pregnancy test.
Healthcare Shares

Is Medibank stock a buy for its 5.5% dividend yield?

This business is providing investors with very healthy dividends.

Read more »