The TSX Composite has had an impressive 2024, gaining 20% year to date and trading comfortably above the psychologically important 25,000 level. Even with a slight pullback in December, investors' optimism remains high as declining interest rates and easing inflation continue to provide a supportive environment for equities.

Some of the year's top-performing TSX stocks like Celestica (TSX:CLS), CES Energy Solutions (TSX:CEU), and MDA Space (TSX:MDA) have led this surge, delivering remarkable returns of up to 264% to investors. But the key question now is: could these top-performing stocks of 2024 maintain their momentum into 2025? In this article, we'll revisit 2024's top three TSX gainers and analyze their fundamental growth prospects, which should help you understand whether they're still worthy of a spot in your portfolio as we head into the new year.

Celestica stock: Up 264%

After skyrocketing by 264% so far in 2024, Celestica is currently the best-performing TSX Composite component. This rally has taken CLS stock price to $141.07 per share, extending its market cap to $16.4 billion.

The recent jump in Celestica's share prices has been driven by robust demand, particularly in its Connectivity & Cloud Solutions segment, which saw a 42% YoY (year-over-year) revenue increase in the third quarter of 2024. Other positive factors like strong execution and operational improvements also boosted its adjusted quarterly earnings up by 60% YoY to US$1.04 per share, which continued to surpass Street analysts' expectations.

Looking ahead, Celestica's guidance for 2025 projects further growth, with its annual sales expected to hit US$10.4 billion and earnings climbing to US$4.42 per share. If the company maintains its strong execution and capitalizes on robust demand in high-growth sectors, CLS stock has the potential to sustain its uptrend in 2025.

CES Energy stock

Similarly, the shares of Calgary-headquartered chemical solutions company CES Energy have zoomed up by nearly 175% year to date to currently trade at $9.47 per share with a market cap of $2.1 billion. With this, CEU stock has surged roughly 640% since the end of 2020.

Over the last 12 months, CES Energy's total revenue rose 5.9% YoY to $2.3 billion. More importantly, its adjusted earnings during the same period jumped by 48.2% to $0.83 per share due mainly to strong growth in its North American operations. In recent quarters, the company has continued to benefit from rising service intensity and its advanced chemical solutions, leading to improved profitability.

With favourable energy sector trends and a shareholder-friendly approach, including dividends and buybacks, I wouldn't be surprised if CES Energy continues to build on this momentum into 2025.

MDA Space stock

Another top performer on the TSX this year has been MDA Space, which has surged by 146% year to date, reaching $28.38 per share and taking its market cap to $3.4 billion.

Even with the ongoing macroeconomic uncertainties, MDA's solid financial growth trends and focus on the fast-growing global space industry have helped it outperform the broader market this year. Looking ahead, MDA Space could continue to maintain this strong momentum into 2025 and beyond.

With a record backlog of $4.6 billion at the end of September 2024, the company has strong revenue visibility to support continued growth. Moreover, its investments in advanced manufacturing facilities and new technologies could help it benefit from rising global demand for satellite systems and space robotics, which should drive its stock higher.