CSL Ltd (ASX: CSL) shares have taken a severe hit over the past year. The stock is down around 34% year to date and roughly 52% over the past 12 months at the time of writing.
That kind of drawdown has forced investors to rethink the once-premium growth story, and analyst sentiment has clearly turned more cautious. Let's break down why.
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Three major pillars
CSL is one of the world's leading biotechnology companies, built on three major pillars. It collects and processes blood plasma through CSL Behring, supplies influenza vaccines through CSL Seqirus, and operates CSL Vifor, which focuses on iron deficiency and nephrology treatments after its major acquisition of Vifor Pharma.
For years, CSL shares were treated as a defensive growth compounder with strong pricing power and resilient demand. That reputation is now being tested as growth slows and integration challenges emerge.
Why CSL shares are under pressure
The sell-off has not come from a single issue. It has built gradually as investors reassess earnings quality, acquisition outcomes, and valuation support.
One of the clearest warning signs has been the downgrade cycle building across FY26 expectations and beyond. Analysts have trimmed revenue and earnings forecasts as they factor in weaker contributions from CSL Vifor and slower growth across parts of the business.
On top of that, CSL has recognised around $5 billion in impairments linked to acquired assets. While these are non-cash charges, they signal that earlier assumptions about the value and performance of those assets may have been too optimistic.
CSL Vifor is proving harder to fix than expected
The real battleground for sentiment is CSL Vifor. The business was supposed to be a strategic growth engine, particularly in nephrology, but it continues to underperform.
Ord Minnett has taken a notably bearish view on CSL shares, arguing the market is still underestimating the scale of the Vifor challenge. The broker explains:
Ord Minnett has reviewed its CSL (CSL) model further with a focus on its Vifor nephrology business that is facing challenges which, in our view, are being underestimated by the broader market. Our estimates for Vifor revenue and operating profit in FY27 are below consensus estimates by 15% and 32%, respectively, while our forecasts for operating profit across the FY27–FY29 horizon are more than 10% below market expectations.
That gap between broker expectations and consensus highlights a simple risk: earnings may still be drifting lower.
Higher interest rates are compressing valuation
The final pressure point is macro-driven. Higher interest rates have hit growth stocks hard, and CSL shares are no exception.
When interest rates rise, future earnings are discounted more heavily. That matters for CSL because a large part of its valuation depends on long-term growth assumptions rather than near-term earnings. As discount rates increase, that long-term value becomes less attractive in present terms.
What next for CSL shares?
CSL is still a global leader in plasma therapies and vaccines, and its core businesses remain highly valuable. However, the market is no longer willing to pay a premium multiple without clearer proof that growth is re-accelerating. That's why analysts at Peak Asset Management have a sell rating on CSL shares.
Until CSL Vifor stabilises and earnings forecasts stop drifting lower, sentiment is likely to remain cautious. For now, the stock is still working through a reset in expectations, and that process rarely happens quickly.
