CSL vs Telstra shares, which should I buy?

A young woman sits with her hand to her chin staring off to the side thinking about her investments.

CSL Ltd (ASX: CSL) and Telstra Group Ltd (ASX: TLS) shares offer investors two very different paths.

One is working through a difficult reset, while the other continues to deliver the steadier performance investors expect from a defensive blue chip.

If I could buy only one today, which would I choose?

The case for Telstra shares

I can see plenty to like about Telstra.

Connectivity has become essential to how Australians work, communicate, shop, travel, and access entertainment. That gives the company a level of demand that many businesses would love to have.

Its mobile division remains the main attraction for me. Telstra has continued growing mobile revenue as customers choose its network and accept higher prices, while cost reductions have also supported earnings.

I also value the income profile. Telstra has been growing its dividend, and its cash flow gives investors a degree of stability that CSL cannot currently match.

The trade-off is the valuation. At a share price of around $5.07, Telstra trades on a price-to-earnings ratio of approximately 25.6 times estimated FY26 earnings of 19.8 cents per share. The multiple remains around 25.4 times based on the FY27 consensus estimate of 20 cents.

That feels quite full when consensus forecasts suggest very little earnings growth between those years.

Why CSL shares look more compelling

CSL shares are trading around $122.61, compared with consensus earnings estimates of $8.22 per share in FY26 and $8.36 in FY27.

That places the biotechnology company on price-to-earnings ratios of approximately 14.9 times and 14.7 times, respectively.

Their sectors and earnings profiles are different, so those multiples need context. But even with that caveat, the gap is hard to ignore.

CSL is cheaper because confidence has collapsed.

Management has reduced its outlook, the Vifor acquisition has underperformed, and growth initiatives are taking longer to improve the financial results. The company has also faced challenges involving US immunoglobulin inventories, albumin pricing in China, research productivity, a change of CEO, and operating complexity.

Those problems could continue testing shareholders. However, the current valuation appears to reflect a deeply pessimistic view of what comes next.

CSL still owns a global plasma collection and manufacturing network that has taken decades to build. Demand for immunoglobulin therapies continues to grow, while large numbers of potential patients remain undiagnosed or untreated.

Management is also simplifying the organisation, improving plasma and manufacturing efficiency, and targeting substantial annual savings by FY28.

The recovery may take time, but I don’t think CSL needs to return immediately to its former market valuation for shareholders to do well from here. Better execution and a return to dependable earnings growth could be enough to change sentiment considerably and support a re-rating.

Which share would I buy?

Telstra would be my choice for an investor who prioritises defensive earnings and dividends.

For my own portfolio, I would buy CSL shares.

The biotech carries greater uncertainty, and another disappointment could send the share price lower. In return for accepting that risk, investors are being offered a much cheaper valuation and what I believe is considerably more upside if conditions improve.

Foolish takeaway

Telstra is doing many of the things shareholders would want to see, but its valuation already gives the company credit for that steadiness.

CSL is being priced as though its recent problems will weigh on the business for years. That could happen, although I think the strength of its core operations gives it a credible route back to growth.

I would be happy to own both shares. But choosing just one at current prices, I think CSL offers the more compelling balance between risk and potential reward.

The post CSL vs Telstra shares, which should I buy? appeared first on The Motley Fool Australia.

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Motley Fool contributor Grace Alvino has positions in CSL. The Motley Fool Australia’s parent company Motley Fool Holdings Inc. has positions in and has recommended CSL. The Motley Fool Australia has positions in and has recommended Telstra Group. 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.