Timing the market is a risky strategy. If you wait too long, you can miss the rally when it inevitably comes. Investors react quickly to news, and so if you've found a good stock at a decent valuation, you shouldn't wait to buy it. Provided you're willing to buy and hold for years, now may be a good time to buy stocks while valuations are low.

A couple of stocks that look particularly good right now include AbbVie (ABBV 0.28%) and Nvidia (NVDA 3.52%). These businesses have promising growth potential, and adding either one of them to your portfolio today could be a great move.

1. AbbVie

Drugmaker AbbVie makes for both a solid growth stock and an income investment. At 4%, its dividend yield is more than twice the S&P 500 average of 1.7%. What makes it even more attractive is that it's also a Dividend King, with a track record for growing its dividend on a yearly basis. In just five years, its dividend payment has increased by 54%. The company's strong free cash flow and solid financials also suggest that more rate increases could be coming.

Fundamental Chart Chart

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Over the past year, the healthcare stock has fluctuated and is up just a modest 2%. At a forward price-to-earnings (P/E) ratio of 14, which is based on analyst expectations, it's trading well below the S&P 500 average of 18.

Investors have probably been discounting AbbVie as a result of the loss in patent protection for its top-selling drug, Humira, which has already begun. But the company's outlook and growth opportunities remain strong; AbbVie has more than 50 programs in its pipeline that are in mid- and late-stage trials that could help the company develop the next blockbuster drug. It has also been heavily investing in research and development, to the tune of $6.5 billion last year.

Plus, AbbVie already has a couple of promising immunology treatments with Skyrizi and Rinvoq, which earned a combined $7.7 billion in revenue last year. Management believes these two medications can reach a higher combined peak than Humira.

When the bull market finally arrives, AbbVie is a stock I would expect should be overdue for a big rally as investors are overlooking a solid business. With such a high yield, thanks in part to the modest price, the stock could be a great deal for investors today.

2. Nvidia

One stock that has already begun to rally this year is Nvidia -- it's up 57% but still down around 20% from its high. The semiconductor stock has benefited from the growing popularity of artificial intelligence (AI) and chatbot ChatGPT. Its business could be fundamental in a shift to companies deploying more AI in their operations. A report from Bloomberg states that Microsoft used "tens of thousands of Nvidia's A100 graphics chips" to create a computer that would help OpenAI develop ChatGPT.

While it's true that the PC market remains soft and that light demand in that area of its business may negatively affect Nvidia's growth in the near future, that shouldn't be a long-term concern; computers have finite lives and are due for routine upgrades. 

What's impressive is that even amid rising costs and headwinds in the tech sector, the company still reported a profit margin of 16% over the trailing 12 months, generating $4.4 billion in profit on sales of just under $27 billion; they were flat compared with the previous year. If that's an underwhelming stretch for Nvidia, I can't wait to see how well the business does when the bull market comes back, the economic outlook is stronger, and businesses are back to spending big money on tech and AI specifically.

The stock's forward P/E multiple of 53 is steep, but Nvidia could still be a great buy, as the need for chips is only going to continue rising. And if Nvidia can maintain its strong profit margin, a lot of that incremental revenue growth will go to the bottom line and strengthen its earnings, making it look like a better buy in the process.