The S&P/ASX 200 Index (ASX: XJO) is having a rough start to the week.
At the time of writing, the benchmark index is down 0.93% to 8,663 points.
That leaves the ASX 200 on track for its second straight decline, after falling 1.51% on Friday.
Across the Pacific, US markets ended last week on a much stronger note. The S&P 500 hit a fresh record high, while the Nasdaq also pushed higher after another strong session for chip stocks.
Locally, though, investors have had plenty to digest this morning.
Here's what is driving the sell-off.
Image source: Getty Images
CSL weighs heavily on the index
The biggest drag today is CSL Ltd (ASX: CSL).
The healthcare giant is having a brutal session after cutting its FY26 outlook and flagging large impairments.
CSL shares are currently down 16.82% to $99.715. Earlier in the session, the stock was down more than 20% and trading near a decade low.
Given CSL's size in the index, today's fall is doing a lot of the damage by itself.
According to The Australian, CSL has shaved about 31 points from the benchmark. The sell-off follows the company's warning that it will recognise around US$5 billion in impairments and lower its earnings expectations.
The damage has also spread across the healthcare sector, with Pro Medicus Ltd (ASX: PME) trading 1.34% lower as well.
Banks and tech names add pressure
Unfortunately, the selling is not just limited to CSL.
Several major banks are also weighing on the index.
Commonwealth Bank of Australia (ASX: CBA) is down 1.6%, while Westpac Banking Corp (ASX: WBC) and National Australia Bank Ltd (ASX: NAB) are also in the red.
ANZ Group Holdings Ltd (ASX: ANZ) is down 3.15% as it trades ex-dividend.
Macquarie Group Ltd (ASX: MQG) is another drag, falling 2.4%.
Technology names are also under pressure, with Xero Ltd (ASX: XRO), and Codan Ltd (ASX: CDA), down 0.54% and 2.55%, respectively.
Oil prices hit sentiment
Brent crude has jumped after US President Donald Trump rejected Iran's latest response to a US peace proposal. Trading Economics shows Brent crude hit above US$104 a barrel earlier today.
That helps explain why Woodside Energy Group Ltd (ASX: WDS) is holding up better than many other large-cap names, up 1.08%.
Resources stocks are also offering some support, with BHP Group Ltd (ASX: BHP) and Rio Tinto Ltd (ASX: RIO) among the stronger performers.
Metcash Ltd (ASX: MTS) is also 6.02% higher after releasing stronger profit guidance.
