CSL Ltd (ASX: CSL) shares have surged 23% across the past two trading days to $166.48, lifting their monthly gain to 34%.
After plunging from $228.30 in October to a low of $90, the recovery is gathering serious pace. Yet CSL remains down 4% year to date and 32% over 12 months.
Can the rebound last?

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Why are CSL shares surging?
The big catalyst was CSL's FY26 result, released on Tuesday.
At first glance, the numbers looked ugly. CSL reported a US$2.6 billion net loss after tax. But that loss wasn't an operating disaster.
It reflected US$7.1 billion of pre-tax impairments and another US$799 million in restructuring costs, largely non-cash. Most of the impairments related to CSL Vifor intangibles and under-utilised property, plant and equipment.
Investors had already been warned. In May, CSL flagged roughly US$5 billion of impairments and cut its FY26 guidance.
Strip away those exceptional items and the picture looks much healthier. Underlying NPATA came in at US$3.1 billion, down just 2%, while revenue slipped 1% to US$15.8 billion — still ahead of analyst expectations.
That gave investors in CSL shares something they had been waiting for: a reset year, a cleaner balance sheet and guidance that finally beat expectations.
CSL Behring remains the powerhouse. Its plasma division generated US$11.4 billion in revenue, down 1%, while immunoglobulin revenue held steady at US$6.2 billion. That's crucial to the bull case.
CSL Vifor grew revenue 3% to US$2.4 billion, while Seqirus struggled, with revenue falling 8% to US$2 billion.
Meanwhile, CSL's transformation program delivered US$176 million of cost savings, and management committed US$1.5 billion to expand US plasma collection capacity.
Guidance is driving the recovery
Here's where things get interesting. CSL expects underlying NPAT to grow approximately 5% in FY27. Consensus had been closer to 2%.
After 18 months of downgraded expectations, that upgrade was a welcome surprise for shareholders in CSL shares. Behring is expected to deliver mid-single-digit growth, with immunoglobulins growing at a mid-to-high single-digit rate.
The weak spot remains Vifor, where revenue is expected to fall about 25% as iron generics arrive.
Are CSL shares fully valued?
Not everyone is convinced the rally can continue. Bell Potter retained its hold rating but lifted its price target from $120 to $150, suggesting CSL shares are now fully valued.
The broker said:
Based on the new underlying NPAT metric, CSL trades on a PE multiple of ~19x FY26 and ~18x FY27 earnings, with flat revenue growth and low-to-mid single digit earnings growth expected for FY27. While the result today suggests the worst (by way of earnings declines) is in the rear-view for CSL, we find it difficult to justify a greater premium than is now being attributed relative to global biopharma peers.
So, while CSL's recovery looks encouraging, the shares have already priced in plenty of optimism. The next challenge is proving that earnings growth can accelerate enough to justify the rally.