The CSL Ltd (ASX: CSL) share price has fallen to its lowest level in almost a decade.

On Monday, shares in the biotech giant dropped to $140.93, marking the lowest level since December 2017.

At the time of writing, the CSL share price has edged slightly higher to $141.30, though it remains down 3.40% for today.

The decline caps off a difficult period for investors. CSL shares have now fallen more than 20% over the past month and are down roughly 45% over the past year.

This makes it one of the weakest performers among ASX healthcare heavyweights.

Rede arrow on a stock market chart going down.

Image source: Getty Images

Investor sentiment turns bearish

One major factor behind the weakness appears to be a major shift in investor sentiment.

CSL was once widely viewed as one of the ASX’s most dependable growth companies. However, recent years have been more challenging. Earnings growth has slowed, and several operational pressures have weighed on the company’s outlook.

Higher plasma collection costs, inflation across global operations, and changing demand patterns following the pandemic have all placed pressure on margins. These factors have made it harder for the company to deliver the strong earnings growth investors had become accustomed to.

In addition, the recent departure of Chief Executive Paul McKenzie has added further uncertainty for investors. McKenzie stepped down in February after three years in the role.

Share price now well below previous highs

The current share price represents a significant fall from CSL’s previous peak.

In August 2025, the company’s shares traded above $270. Since then, the stock has been trending steadily lower as investors reassess growth expectations for the biotech group.

Technical indicators also highlight the extent of the decline. The chart shows CSL recently trading near the lower end of its Bollinger Bands, while the relative strength index (RSI) has moved into oversold territory.

This suggests the stock has come under heavy selling pressure in recent weeks and highlights its weak momentum.

Long-term fundamentals remain closely watched

Despite the recent weakness, CSL remains one of Australia’s most globally recognised healthcare companies.

Founded in Melbourne more than a century ago, the group operates across 3 major divisions: CSL Behring, CSL Seqirus, and CSL Vifor. Its therapies focus on areas such as plasma-derived medicines, vaccines, and treatments for rare diseases.

Demand for plasma-based therapies continues to grow globally, driven by ageing populations and increasing diagnoses of chronic conditions.

Foolish Takeaway

CSL’s fall to a 9-year low shows how much investor sentiment has deteriorated toward the biotech giant.

While the company still operates a large global healthcare business, investors are waiting for clearer signs that earnings growth is improving.

With shares now trading at levels last seen in 2017, CSL has become one of the most closely watched healthcare stocks on the ASX.