Some investors believe you make money when you buy a stock, not when you sell it. The logic behind this idea is that investing in the right stock at the right time -- and holding onto it for a while -- is one of the best formulas for earning terrific returns.

So, a company being near its 52-week low is no reason to avoid it. On the contrary, that might be the best time to invest, provided there are good reasons to believe it will bounce back.

With that in mind, let's consider two stocks that haven't performed well recently and are now near their 52-week lows but that are still worth investing in: CRISPR Therapeutics (CRSP 1.77%) and Amgen (AMGN 0.69%).

1. CRISPR Therapeutics

CRISPR Therapeutics is a mid-stage biotech specializing in gene editing. The company has just one product on the market, Casgevy, which treats transfusion-dependent beta-thalassemia and sickle cell disease, two rare blood disorders. Casgevy has been on the market for a little more than a year. It became the first gene-editing treatment that uses the Nobel Prize-winning CRISPR technique, an impressive achievement by CRISPR Therapeutics.

That said, due to the complexity of administering gene-editing treatments, it is not yet generating revenue for CRISPR. That, combined with the fact that the drugmaker remains unprofitable, explains why it is significantly lagging the market. However, there is much to like about CRISPR Therapeutics. First, Casgevy's potential is large, even if the biotech will share the spoils with Vertex Pharmaceuticals, with whom it developed the medicine.

With little competition on the market for Casgevy, a price of $2.2 million in the U.S., increased third-party coverage, and a total target population of at least 58,000 patients, the medicine should generate well over $1 billion in sales at its peak. Second, CRISPR has several other promising pipeline candidates.

Recently, the U.S. Food and Drug Administration (FDA) granted the Regenerative Medicine Advanced Therapy (RMAT) designation to the company's CTX112, a potential therapy for certain B-cell malignancies. This designation is reserved for investigational medicines that meet certain conditions, including targeting a serious or life-threatening disease with few treatment options and having produced promising preliminary evidence of efficacy.

It also helps speed up the development of therapies. So, this was a big deal for CRISPR. The biotech has several other exciting candidates beyond CX112. There are some risks associated with CRISPR Therapeutics. Its pipeline programs, even CX112, could flop, for instance, a typical issue biotech companies -- especially smaller ones -- have to deal with. However, CRISPR Therapeutics' shares could soar if it makes progress with its pipeline and Casgevy starts ramping up its sales.

For those comfortable with the risk, it is worth investing in the stock.

2. Amgen

The market recently punished Amgen's shares after its leading weight loss candidate, MariTide, failed to impress in a mid-stage study. The stock has rebounded somewhat since that debacle, but it is not very far from its 52-week low. However, the market's reaction was perhaps a bit overdone. MariTide led to a 20% average weight loss after 52 weeks, with no weight loss plateau observed.

That's not bad at all. The biotech still has to conduct phase 3 studies, but if these confirm MariTide's mid-stage trial performance, the medicine could carve out a small niche in the rapidly rising weight loss space. There are many other reasons to invest in Amgen. For instance, the company's financial results remain strong. Amgen's 23% year-over-year revenue growth to $8.5 billion in the third quarter was due to an acquisition, but its sales still jumped by a strong 8% year over year organically.

Amgen has several products that should drive top-line growth for many years, including Tepezza, the only medicine for thyroid eye disease approved by the FDA. The company's Tezspire, the rights of which it shares with AstraZeneca, is growing its sales fast and recently aced a phase 3 study that should lead to a label expansion. Further, Amgen has a deep pipeline that includes at least one other potential weight loss candidate and plenty of products beyond that.

Lastly, Amgen is a terrific dividend stock. The company has increased its payouts by 201% in the past decade, and the stock currently offers a forward yield of 3.63% compared to the S&P 500's 1.27%. So, Amgen is an excellent stock for long-term, income-seeking investors.