SYDNEY, March 20, 2026, 09:38 UTC+11.
CSL shares fell again on Thursday, ending at A$134.62, down 2.45%, even as the Australian biotech kept buying back stock. An ASX filing dated March 19 showed CSL repurchased 74,167 shares on March 18 for A$10.3 million at prices between A$138.00 and A$141.15 under an on-market buyback that can run to June 30, 2026 and is sized at up to US$750 million. 1
That leaves the stock below the A$141.03 level where it appeared on an ASX 200 52-week low list last week, when it was already down 43.1% from a year earlier. This has started to look like more than a post-results wobble. 2
The selloff traces back to February, when CSL reported an 81% drop in first-half profit, hit by weaker plasma and vaccine sales, one-off charges and the abrupt departure of chief executive Paul McKenzie. Reuters reported the stock then fell to its lowest level since April 2018. 3
Thursday’s selloff was broad, with Australia’s benchmark ASX 200 down 1.65%, but CSL still fell more than the market. 4
Morningstar analyst Shane Ponraj wrote on March 11 that CSL’s “current headwinds appear more structural” and cut his fair value estimate by 22% to A$210. He said tighter competition in plasma therapies – medicines made from donated blood plasma – could force more flexible pricing and leave only modest margin recovery. 5
The competitive picture is not simple. Morningstar says Seqirus remains the world’s second-largest influenza vaccine business behind Sanofi, while Roche’s Hemlibra is one of the newer therapies weighing on growth in hemophilia, one of CSL’s long-held franchises. 6
CSL has tried to answer that pressure with fresh investment and pipeline news. In the past two weeks it broke ground on a $1.5 billion expansion of its Illinois plasma plant, and in February it gave Eli Lilly rights to develop clazakizumab in other indications for a $100 million upfront payment; R&D head Bill Mezzanotte called the drug a “promising therapeutic candidate.” 7
When the board installed Gordon Naylor as interim CEO last month, David Tuckwell, chief investment officer at ETF Shares, said it was “prioritising the fix” of the division “dragging down the stock” and called the move “possibly a salvage mission.” 8
But the risk is plain. If plasma pricing stays tight and margin recovery remains slow, the shares can stay under pressure even after a steep selloff. 5
