Semiconductor stocks have been in rally mode since the beginning of July, which is evident from the 22% spike in the PHLX Semiconductor Sector index.

The rally in semiconductor stocks has rubbed off positively on the likes of Advanced Micro Devices (AMD -5.44%) and Micron Technology (MU -4.61%). While AMD stock has soared nearly 36% since the beginning of July, Micron has gained almost 15%.

The spike in AMD stock seems justified, as the company has been reporting terrific results thanks to the healthy demand for its chips. However, the same cannot be said about Micron, as the memory specialist has lost its wheels thanks to a downturn in memory prices. Does this mean that AMD is in a better position to sustain its hot rally and investors should buy its shares over Micron? Let's find out.

Chart showing rise in AMD's and Micron's prices, and in the PHLX Semiconductor Sector, in July.

^SOX data by YCharts

AMD is on a roll

AMD released its second-quarter results on Aug. 2, reporting a 70% year-over-year increase in revenue to a record $6.6 billion. The company's operating margin expanded six percentage points over the prior-year period, leading to a 67% year-over-year jump in adjusted earnings to $1.05 per share.

AMD saw impressive growth across all its business segments last quarter, with the data center segment standing out with an 83% year-over-year spike in revenue to $1.5 billion. The acquisition of Xilinx also boosted AMD's top line and margins. The acquisition sent the company's embedded segment revenue to $1.3 billion, a massive year-over-year spike of 2,228%.

The chipmaker expects to finish the year with $26.3 billion in revenue. That would be a 60% increase over 2021. More importantly, the diverse markets that AMD serves suggest that the company's impressive growth is here to stay for a long time.

For instance, AMD's gaming revenue was up 32% year over year in the quarter to $1.7 billion. The segment's impressive growth was driven by a bump in sales of semi-custom chips to gaming console manufacturers such as Sony, Microsoft, and Valve. All three companies use AMD's semi-custom chips to power their consoles, and the good part is that they are witnessing solid demand this year that has prompted manufacturers to increase production.

Meanwhile, AMD management claims that the company has gained market share in the PC (personal computer) processor market for nine quarters on the trot, thanks to the healthy demand for chips used in notebooks. Wedbush Securities estimates that AMD could keep gaining market share in PCs for the next couple of years from rival Intel. That isn't surprising, as AMD enjoys a technology lead over Intel that has allowed it to report impressive growth even when PC sales are declining big time.

In all, AMD's market share gains in data centers and PCs and secular growth opportunities in the gaming console space are some of the reasons why analysts expect its earnings to grow at an annual pace of nearly 27% over the next five years. So, AMD could remain a top growth stock in the long run.

Micron Technology is in a tough spot

Micron Technology is in the soup right now thanks to an oversupply in the memory market. While AMD has been able to offset the PC market weakness by gaining more share against Intel, Micron hasn't been able to do the same.

The company's days of terrific growth are now a thing of the past, as the demand for memory chips has dwindled and prices are declining. This explains why Micron now warns that its fiscal 2022 fourth-quarter revenue "may come in at or below the low end of the revenue guidance range provided in our June 30 earnings call."

Micron delivered a disappointing guidance toward the end of June, missing analysts' expectations by a huge margin as it expects top and bottom lines to contract in the current quarter. The company had guided for $7.2 billion in revenue (plus or minus $400 million) at the midpoint of its guidance range, but it looks like it is finding it difficult to meet that mark now.

Micron warns that the challenging memory environment is here to stay for at least a couple of quarters. That's why the company has reduced its fiscal 2023 capital expenditure forecast, stating that its outlay next fiscal year would "be down meaningfully versus FY22." Analysts are forecasting Micron's revenue and earnings to shrink in fiscal 2023.

The verdict

AMD is the clear winner of this showdown, as it is on track to maintain its solid growth even in a tough environment. Micron, on the other hand, won't be able to recover until and unless there is a turnaround in the memory market. The bad news for Micron is that the growth in memory demand in 2023 is expected to be just 8.3%, falling below 10% for the first time ever.

High inflation and fears of an economic downturn are expected to weigh on memory demand. Supply, however, is expected to increase by 14%, leading to an oversupply in the market and lower prices. That's why investors looking to buy a semiconductor stock right now should consider choosing AMD over Micron, as the former has the potential to sustain its rally on the back of its tremendous growth.