Wall Street is getting increasingly worried about a stock market crash. Goldman Sachs analysts contend that inflated valuations have increased the risk of a correction, while Morgan Stanley analysts have cut their rating on U.S. equities to underweight citing risks to growth. There are a few more telltale signs of a potential crash in the cards, all of which have thrown the S&P 500's robust rally out of gear in September.

However, the September sell-off provides a great opportunity for savvy investors looking to invest in solid companies for the long run. Apple (AAPL 0.06%) and Nvidia (NVDA -2.61%) are two such stocks that investors may consider buying hand over fist amid the ongoing correction. Let's see why.

Person using mobile phone to look at a stock chart.

Image source: Getty Images.

1. Apple

Trading at 28.5 times trailing earnings, Apple is trading at a discount to the S&P 500's earnings multiple of 31. This already makes Apple an attractive stock to buy given its impressive history of growth and a new sales driver in the form of the iPhone 13, and a September sell-off gives investors the opportunity to buy it at a cheaper valuation.

The tech giant has been enjoying terrific growth with its revenue increasing 36% year over year in the third quarter of fiscal 2021 to $81.4 billion, with the iPhone accounting for 49% of the top line. Apple's iPhone revenue had increased 50% year over year in the quarter that ended in June, and the iPhone 13 can help the company sustain that momentum by increasing its market share.

For instance, the aggressive pricing of the iPhone 13 lineup in China, which makes it cheaper than the launch prices of the iPhone 12, as well as the lack of competition in the high-end smartphone market from the likes of Huawei, is expected to be a tailwind for the device. Apple has reportedly received more than 5 million preorders for the iPhone 13 in China across different online platforms such as Alibaba's Tmall.com and JD.com.

JD.com reported 2 million preorders for the iPhone 13, which exceeded the 1.5 million preorders received for the iPhone 12 last year. Market research firm Canalys reports that Apple's share of the Chinese smartphone market had increased to 43% in the second quarter of 2021 from 28% in the year-ago period, and the iPhone 13 can push that number higher. Moreover, a survey carried out by Strategy Analytics in June revealed that 70% of buyers were planning to upgrade their devices, and 90% of respondents wanted 5G in their next device.

With China expected to account for 47% of 5G smartphone shipments this year, the iPhone 13 seems to have put Apple in a nice position to tap into the same. Meanwhile, the production constraints faced by Android original equipment manufacturers will also be a tailwind for the iPhone 13. The supply shortage of high-end Android devices is expected to help Apple gain more market share in the U.S.

In all, Strategy Analytics estimates that the iPhone 13 can push Apple's share of the 5G smartphone market to 40% from 29%. Additionally, investors shouldn't forget that the 5G smartphone market is set to grow rapidly in the future, generating an estimated $337 billion in revenue by 2025 as compared to an estimated $108 billion this year.

Apple is one of the best bets to take advantage of this opportunity as the iPhone 13 is expected to further increase its 5G market share. So, the iPhone looks set to record multi-year growth thanks to 5G smartphones, driving Apple's revenue and earnings higher in the process since it moves the needle in a big way for the company.

All of this makes Apple a top 5G stock to buy in the event of a market correction as it gives investors a ticket to take advantage of a red-hot secular growth opportunity.

A closeup view shows the Nvidia Drive Platform for use in Hyundai vehicles

Nvidia's automotive business has started accelerating in recent years. Image source: Nvidia.

2. Nvidia

Nvidia is an expensive stock to buy with a price-to-earnings ratio of 78. The chipmaker's rich valuation is justified by the explosive growth that it has been consistently delivering on account of its dominant position in the graphics card market and increasing influence in other areas such as data centers and automotive.

The company's fiscal 2022 Q2 revenue increased a whopping 68% year over year to $6.5 billion and adjusted earnings shot up 89% year over year to $1.04 per share. So, investors shouldn't miss the opportunity of buying this fast-growing company if its shares pull back on account of a broad market correction, especially considering the multiple growth drivers it can benefit from.

The video gaming hardware market is Nvidia's biggest catalyst, with the segment producing 47% of its revenue last quarter. Jon Peddie Research says Nvidia controlled 83% of the discrete GPU market in the second quarter of 2021, which is the biggest reason why you may want to buy the stock. That's because the discrete graphics card market's size is expected to jump from $29 billion last year to $44 billion in 2023.

So, Nvidia could generate substantial incremental revenue from graphics card sales in the future thanks to its massive market share and a huge installed base of users in an upgrade window. Meanwhile, Nvidia's robust position in the nascent cloud gaming market will be an additional tailwind. Newzoo estimates the cloud gaming market could generate $6.5 billion in revenue by 2024 from just $669 million in 2020.

Nvidia's cloud gaming service -- GeForce NOW -- has already gained 10 million subscribers, which is impressive considering that the cloud gaming market is expected to hit 24 million paying subscribers by the end of 2021. So, a strong market share in cloud gaming can further boost the terrific growth of the company's gaming business.

On the other hand, Nvidia's automotive business has started accelerating as the design wins the company scored in this segment are translating into revenue. The company expects the automotive business to generate $8 billion in revenue over the next five years, which points toward a nice bump in the segment's performance as compared to the $576 million revenue generated in the past year.

And finally, Nvidia is well placed to dominate the massive data center market as well thanks to new chips and software-based offerings. The chipmaker is reportedly sitting on an addressable opportunity worth $100 billion in data centers, which explains why this segment's revenue has been growing at a high clip. Nvidia's data center revenue had increased 35% year over year last quarter as the company's graphics cards dominated the supercomputer market and cloud customers bought more of its chips.

In the end, it is not surprising to see why analysts estimate Nvidia's earnings to clock a 30%-plus growth rate for the next five years, which makes buying this growth stock on the dip a no-brainer.