With the first half of 2024 nearly gone, investors may wonder which stocks have more upside ahead by the year’s end and beyond. Many names have struggled in the face of high interest rates and recession fears. However, several skyrocketing stocks have defied skeptics and capitalized on favorable tailwinds.

As we enter the hot summer months, lower inflation, potential interest rate cuts and the transformative impact of artificial intelligence (AI) are key factors shaping a favorable environment for investors looking to strike while the iron is hot.

Some compelling opportunities still remain for skyrocketing stocks. They could continue surging ahead thanks to strong growth trends, diversified offerings, or accelerating business momentum even in a potentially turbulent market.

However, past performance is no guarantee of future success. Still, the remarkable rallies of these stocks serve as a reminder of the potential rewards of identifying and investing in game-changing companies early on.

Three stocks have already achieved over 70% in the first half of 2024. Yet, they still have triple-digit upside potential and are poised to continue delivering outsized returns.

Celestica (CLS)

Celestica (NYSE:CLS) is a Toronto-based multinational electronics manufacturing services (EMS) company offering various services in different industries. Its resilient and adaptable manufacturing solutions benefit from diversified revenue streams. The tech company has been investing in advanced manufacturing technologies, including AI. Moreover, it continues to expand into high-growth verticals like cloud computing and healthcare.

Celestia’s shares have already surged 120% in 2024. The company reported revenue growth of 20% year-over-year (YOY), driven by the Connectivity & Cloud Solutions (CCS) segment growth. It achieved a 24% and 16% cost reduction in finance and Selling, General, and Administrative (SG&A) expenses. As a result, it expanded its operating margin to 6.2% from 5.2% YOY. The non-IFRS adjusted EPS increased 42.42% YOY, and guidance has been raised by 22.22%

Despite trading 90% higher year-to-date (YTD), CLS stock stands approximately 10% below its May high. This is still 55% below its 2000 record, making CLS one of the stocks with more upside ahead. Although it may be only slightly undervalued compared to the hardware industry, it trades only 0.80x its sales.

IES Holdings (IESC)

IES Holdings (NASDAQ:IESC) is another diversified holding company that is seen as one of the stocks with more upside ahead. The construction company owns and manages a portfolio of subsidiaries operating across various sectors, primarily focusing on electrical and mechanical design, installation and maintenance. With a $552.85 billion investment in public infrastructure and falling interest rates and inflation, IES’s services in renewable energy, telecommunications, and smart city projects may continue to be in high demand.

IESC stock has already gained 140% this year but trades at 69% YTD, indicating the stock is pulling back, albeit in a growth phase. The shares skyrocketed following its Q1 earnings in May, where it reported a 146% increase in operating income. A 24% revenue increase was driven by increased demand in data centers and custom power solutions. The company had no debt and an increased backlog of 27% compared to Q2 2023. It also raised Non-IFRS adjusted free cash flow (FCF) guidance by 25% from $200 million and Non-IFRS adjusted EPS by 22.22%.

Based on its P/E ratio of 20.2x and the annualized earnings growth rate of 144.91%, IESC’s PEG ratio of approximately 0.14x suggests that IES could be substantially undervalued relative to its earnings growth potential. A fair PEG ratio is typically around 1x.

NRG Energy (NRG)

NRG Energy (NYSE:NRG) also operates a diverse portfolio of power-generating facilities boasting a strong customer base. Its retail electricity business provides stable cash flows, which may include government-established funds. As the company transitions from a traditional utility to a renewable energy leader, cleaner sources position it for long-term growth. This is even more relevant now as the U.S. announced $6 billion for energy independence and emissions reduction.

NRG shares are up over 56% YTD, while the utilities sector underperformed. The company managed to reverse a net loss of $1,335 million in Q1 2023 into a net income of $511 million in Q1 2024. Adjusted EBITDA increased 31.41% YOY. NRG’s price-to-earnings (P/E) ratio of 11.55x is well below the industry average of 16.75x. This positions the firm as one of the stocks with more upside ahead. It is expected to increase approximately 45% to reach industry valuation and (barely) claim triple-digit gains.

Despite substantial debt due to prior acquisitions, NRG went from using $1,598 million in cash in Q1 2023 to generating $267 million in Q1 2024 while reaffirming share repurchases. Its strong return on equity (ROE) of 51.56% indicates efficient use of shareholder capital. Combined with a forward dividend yield of 2%, it appeals to investors seeking exposure to increased demand for (green) electricity. 

On the date of publication, Stavros Tousios did not have (either directly or indirectly) any positions in the securities mentioned in this article. The opinions expressed in this article are those of the writer, subject to the InvestorPlace.com Publishing Guidelines.