CSL Ltd (ASX: CSL) stock had an underwhelming year in 2024.

During the 12 months, the biotechnology giant's shares traded relatively flat and underperformed the market.

While this is disappointing, has it created a buying opportunity for investors in 2025? Let's find out.

CSL stock: Buy, hold, or sell in 2025?

The good news is that almost all the major brokers currently have the equivalent of buy ratings on CSL's shares at the start of 2025.

The even better news is that the general consensus is that CSL stock could generate big returns over the next 12 months.

Let's look at what a few brokers are saying about the plasma therapies leader.

Over at Morgans, its analysts have an add rating and $330.75 price target on the company's shares. This implies potential upside of almost 15% for investors from current levels.

The broker recently named CSL as one of its Best Calls to Action. It notes that these are "stocks that present compelling buying prospects right now."

Elsewhere, analysts at Macquarie have an outperform rating and $334.00 price target on CSL stock. This suggests that upside of approximately 16% is possible over the next 12 months.

In addition, the broker has previously stated its belief that CSL's shares could hit $500 within three years. This is based on its forecast for strong double-digit earnings growth for the foreseeable future thanks to the CSL Behring plasma business.

What else?

UBS is also bullish on CSL and has a buy rating and $330.00 price target on its shares, and Jarden has an overweight rating and $329.62 price target on them.

But the most bullish broker is arguably Bell Potter, which has a buy rating and $345.00 price target. This implies potential upside of almost 20% for investors in 2025.

Commenting on its buy rating, the broker said:

We expect CSL will achieve guidance of "annual double-digit earnings growth" over the mid-term driven largely by the legacy plasma business, Behring, particularly its immunoglobulin sales. While CSL's Seqirus and Vifor business units do face near-term headwinds (reduced flu market demand and generic iron competition), these two units combined only contribute less than a third of total earnings.

CSL continues to be a high quality, global operator with a multi-year gross margin recovery well underway to drive earnings expansion. The stock is currently trading at a 12m forward PE 27% and 19% below 5- and 10-year averages, respectively.

Overall, this could make the biotech giant one to consider this year.