CSL stock price sinks despite buyback as pressure builds on Australian biotech

CSL stock price sinks despite buyback as pressure builds on Australian biotech

March 20, 2026

SYDNEY, March 20, 2026, 09:38 UTC+11.

CSL shares slid another 2.45% on Thursday, closing at A$134.62, while the company pressed ahead with its buyback program. According to an ASX filing dated March 19, CSL snapped up 74,167 shares on March 18, spending A$10.3 million at prices ranging from A$138.00 to A$141.15. The on-market buyback, capped at up to US$750 million, is scheduled to run through June 30, 2026.

The stock is still trading under A$141.03, after landing on last week’s ASX 200 52-week low list. At that point, it was already off 43.1% over the past year. The slide now feels steeper than just a brief dip after earnings.

CSL shares have been sliding since February, after the company stunned investors with an 81% plunge in first-half profit. The numbers reflected sluggish plasma and vaccine sales, various one-off costs, and the sudden exit of CEO Paul McKenzie. According to Reuters, the stock tumbled to lows not seen since April 2018.

Australia’s ASX 200 slipped 1.65% on Thursday in a sweeping decline, but shares of CSL underperformed, dropping even harder than the index.

CSL faces what look like deeper, structural hurdles, Morningstar’s Shane Ponraj said in a March 11 note, slashing his fair value estimate for the stock by 22% to A$210. He flagged stiffer competition in plasma therapies—drugs derived from donated blood plasma—as a pressure point, warning that pricing may need to bend, limiting any bounce in margins to just modest gains.

The landscape is complicated. Morningstar puts Seqirus as the world’s No. 2 flu vaccine player, trailing only Sanofi. Over in hemophilia, Roche’s Hemlibra is among the newer entrants pressuring growth in a business CSL has dominated for years.

CSL is pushing back against the pressure, putting money to work and touting new pipeline moves. In just the last two weeks, the company kicked off a $1.5 billion expansion at its Illinois plasma facility. Back in February, Eli Lilly agreed to pay $100 million up front for rights to develop clazakizumab in additional indications. R&D chief Bill Mezzanotte described the asset as a “promising therapeutic candidate.” Global Newsroom | CSL

After the board brought in Gordon Naylor as interim CEO last month, ETF Shares’ chief investment officer David Tuckwell described the decision as “prioritising the fix” for the division “dragging down the stock,” even going so far as to call it “possibly a salvage mission.” Reuters

The risk is clear enough: tight plasma pricing and sluggish margin recovery could keep the shares pinned down, even after a sharp drop.

Marcin Frąckiewicz

Marcin Frąckiewicz is the CEO of TS2 Space and a longtime technology entrepreneur focused on telecommunications, satellite communications and digital innovation. A graduate of the Warsaw School of Economics (SGH), he writes about space technology, artificial intelligence and publicly traded technology companies. His analysis covers major market trends, emerging technologies and the businesses shaping the future of the global economy.

Stock Market Today

  • How Andy Burnham’s Premiership Could Impact Key FTSE 100 and FTSE 250 Stocks
    June 22, 2026, 7:10 AM EDT. Andy Burnham's potential as UK Prime Minister could significantly affect key UK shares, notably Vistry Group (FTSE 250) and Compass Group (FTSE 100). Vistry, a leading housebuilder focusing on social and affordable housing, stands to benefit from Burnham's emphasis on council homes to tackle the housing shortage, potentially securing longer contracts and greater stability away from private market volatility. However, social housing's lower profit margins might limit upside during market recoveries. Compass Group, a global catering giant, could gain from anticipated increased public spending funded by higher taxes on wealthier individuals, especially in education and health sectors. Investors should weigh these dynamics carefully as UK political leadership shifts with Keir Starmer stepping down by September.