CSL shares rebound 86%: Is the ASX biotech stock a buy, sell or hold for September?

CSL Ltd (ASX: CSL) shares have slid slightly into the red in Wednesday lunchtime trade.

At the time of writing, the ASX biotech stock is down around 0.2% and is changing hands at $172 a piece.

Despite the softer share price today, CSL shares are still up a huge 38% over the past month alone, have rebounded 86% from a multi-year low in early-June, and are now roughly flat for the year-to-date.

What has driven CSL shares higher over the past month?

After a difficult 18 months, including several market and company headwinds, it looks like investor sentiment around CSL shares have finally turned a corner and the worst could finally be over. And it appears to be driven by several tailwinds.

It looks like investors finally realised that the CSL share sell-off was overdone, and the shares were selling too cheap compared to the underlying business. 

At the same time, it looks like ASX healthcare shares have come back into favor after a significant sell-off. CSL hasn’t moved in isolation, either. Australian healthcare stocks have staged a major recovery, with the healthcare index rising more than 20% in a month recently.

The S&P/ASX 200 Health Care Index (ASX: XHJ) has jumped 17% higher over the past month as investors rotate back into the sector.

CSL shares were boosted even higher after it posted an impressive FY26 result in mid-August.

CSL reported total revenue of US$15.8 billion and NPAT of US$2.6 billion. It also recorded a net loss after tax of US$2.6 billion for FY26, coming from pre-tax impairments and restructuring costs. 

CSL management describes FY26 as a ‘reset year’, with FY27 marking a return to growth.

The result came in way ahead of guidance and investors rushed to snap up the shares.

Are the shares a buy for September?

I think there is a lot of potential for the company to grow over the next few years. CSL is operating in a high-growth market, and its blood plasma division dominates the market for rare blood disorders and immunoglobulin products.

The company’s growth initiatives are clearly working. But it’s likely it will take a while longer to see the financial benefits.

At the moment, forecasts suggest the experts are mostly on the fence. But after the latest price spike, many think we’ll see a downside ahead. 

Market Index data shows that brokers are split between a buy and a hold rating on CSL shares. The $153.21 average target price now implies a potential 11% downside, at the time of writing.

Sentiment is similar on TradingView. The majority (10 out of 18) have a hold rating on the stock. However, the other eight rate CSL shares as a buy/strong buy.

The average $168.13 target price is higher, but it still implies a potential downside of around 2%, at the time of writing.

I’d consider adding them to my portfolio in September, but I’d be wary of exactly how much upside, if any, it left after CSL shares rallied in August.

The post CSL shares rebound 86%: Is the ASX biotech stock a buy, sell or hold for September? appeared first on The Motley Fool Australia.

More reading

• The 5 best ASX 200 stocks to buy and hold in August revealed
• Top 3 ASX shares to buy in September 2026
• CSL shares are up more than 40% in a month. What just happened in the US?
• 5 things reporting season taught ASX investors about FY27
• Where will CSL shares be in 12 months? Brokers weigh in

Motley Fool contributor Samantha Menzies has no position in any of the stocks mentioned. The Motley Fool Australia’s parent company Motley Fool Holdings Inc. has positions in and has recommended CSL. The Motley Fool Australia has recommended CSL. The Motley Fool has a disclosure policy. This article contains general investment advice only (under AFSL 400691). Authorised by Scott Phillips.