The first half of the year hasn't been great for the likes of Cirrus Logic (CRUS 2.42%) and Advanced Micro Devices (AMD -0.35%). Share prices of both companies have headed south so far in 2021.

But that may not be the case forever as Cirrus Logic and AMD are sitting on a bunch of terrific growth drivers that could turn their stock price fortunes around in the second half of the year.

Let's look at the reasons why investors might be wise to put down $1,000 on these two stocks right now.

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1. Cirrus Logic 

It is no secret that Apple's (AAPL 1.27%) 5G-enabled iPhone 12 models have been a huge hit among customers, sending the smartphone giant's revenue and earnings north in a spectacular manner. Cirrus Logic has reaped the benefits of the same as Apple is the chipmaker's largest source of revenue, accounting for 76% of the top line last quarter. The iPhone maker had produced 83% of Cirrus' total revenue in fiscal 2021 that ended in March.

Man pointing up to an upward sloping line.

Image source: Getty Images.

Not surprisingly, Cirrus' top and bottom lines stepped on the gas in the second half of 2020 after showing signs of plateauing earlier last year. The company delivered $780 million in revenue in the second half of fiscal 2021 that ended in March this year, up 19% year over year.

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However, Cirrus investors were in for a scare after the company's guidance for the first quarter of fiscal 2022, which ends this month, failed to meet expectations. The chipmaker blamed supply chain issues for its failure to meet expectations as it was unable to meet the robust end-market demand. Additionally, Apple may have rolled back orders for the iPhone 12 series as the supply chain is already in motion to roll out this year's models.

However, Cirrus did provide a hint that its business will pick up the pace in the second half of the year. CEO John Forsyth said on the April earnings conference call:

In the coming months, we will begin shipping new technologies to our customers across a range of end devices, including important new content in the high-performance mixed-signal category. And based on these factors, we expect to accelerate revenue growth in FY 2022.

Cirrus' confidence isn't misplaced as its largest customer is expected to witness a big boom in sales. Reports suggest that Apple's suppliers have already started making components for this year's iPhones. What's more, the company is expected to bump its initial production of the 2021 iPhone lineup by 25% to 100 million units as compared to the iPhone 12's initial order size of 80 million units, according to Dan Ives of Wedbush. He also adds that Apple could finish 2021 with nearly 250 million units in sales, which would be its highest since 231 million sold in 2015.

The iPhone's terrific momentum is expected to continue in 2022. Juniper Research estimates that Apple could sell $200 billion worth of iPhones next year, which doesn't look like a very ambitious target as the company has generated over $113 billion in iPhone revenue over the past six months.

These tailwinds should help Cirrus shares break out from their mediocrity and set the market on fire in the future. So, investors looking to add a growth stock to their portfolio should seriously consider Cirrus Logic as it trades at an attractive forward earnings multiple of just 15.

2. AMD

It is startling to see AMD stock taking a beating in 2021 considering the pace at which the chipmaker has been growing. The company delivered outstanding results in 2020 and it has continued in the same vein in 2021, with revenue increasing a whopping 93% in the first quarter to $3.45 billion.

AMD aims to clock 50% revenue growth this year, which would be better than its 2020 revenue increase of 45%. However, AMD can exceed its own expectations. The company had given investors a glimpse of the same when it reported its first-quarter results in April and raised its full-year revenue guidance. It was originally anticipating a 37% year-over-year increase in 2021 revenue, but a robust demand environment has encouraged AMD to raise guidance substantially.

There are three reasons why AMD can turn in better-than-expected results: a short supply of graphics cards leading to a sharp spike in prices, market share gains against Intel (INTC 0.64%) in the server and PC processor markets, and the rapidly growing sales of the latest gaming consoles.

AMD's computing and graphics segment, which recorded 46% year-over-year revenue growth in the first quarter to $2.1 billion and accounted for nearly 61% of the total revenue, is poised to benefit from two of those tailwinds. According to AMD, a mix of higher sales volumes and stronger average selling prices (ASPs) of the Ryzen CPU (central processing unit) and Radeon GPU (graphics processing unit) products drove the segment's impressive growth.

For instance, sales of AMD's Radeon 6000 series high-end GPUs doubled quarter over quarter. AMD says that this is just the beginning as the Radeon 6000 series sales could "grow significantly over the coming quarters as we ramp production," indicating that the company is trying to address the problem of short supply. Even better, the GPU market is poised for long-term growth. Jon Peddie Research forecasts sales of discrete graphics cards to hit $54 billion in 2025 from $23.6 billion last year.

AMD is one of the two major players in this space, holding a market share of nearly 20%. It is trying to make a bigger dent in the market with new technologies, so don't be surprised to see it win big from GPUs in the future. Meanwhile, AMD's improving market share in the PC processor market thanks to the success of its Ryzen CPUs is turning out to be another catalyst.

According to a survey carried out by popular video game distribution service Steam, AMD now has just over 30% of the CPU market under its control, with Intel commanding the rest. It is worth noting that AMD's market share was less than 20% in 2017. But AMD's technological advantage over Intel has helped it take away share from its bigger rival. The trend may not change anytime soon thanks to AMD's superior manufacturing process.

Finally, AMD's enterprise, embedded, and semi-custom (EESC) business is riding on two solid catalysts. One of them is AMD's market share gains against Intel in the server market. AMD's superior manufacturing process has allowed it to increase its market share to nearly 9% at the end of the first quarter of 2021 from almost nothing at the end of 2017, according to Mercury Research.

AMD investors can expect the company to take more market share away from Intel in the server space thanks to the former's Milan processors that are reportedly more powerful than Chipzilla's offerings. Throw in the terrific momentum of the new console cycle that has given AMD a big shot in the arm, and investors have another solid reason to buy this top tech stock that is trading at just 34 times trailing earnings as compared to the five-year average multiple of 124.