Investor Ben Graham -- mentor to the Oracle of Omaha himself, Warren Buffett -- was once quoted as saying: "The individual investor should act consistently as an investor and not as a speculator."

And great companies with long-term growth potential aren't found by looking at share price alone. Instead, focus on companies with compelling products or services that are uniquely situated in industries primed for durable growth -- and that have the leadership to bring the business forward to capitalize on that growth story. 

Here are two such businesses to consider adding to your portfolio if you have $2,000 to invest in stocks right now. 

1. Vertex Pharmaceuticals 

Vertex Pharmaceuticals (VRTX -0.06%) is looking to change the way people live with rare diseases. With a focus on underserved areas of the rare disease drug market, the biotech has developed a cash-rich and profitable business. Right now, the company has four approved products on the market. 

All of these drugs are CFTR modulators, which target the underlying cause of the genetic illness cystic fibrosis. And given that Vertex is the only company with approved CFTR modulators, it has a virtual monopoly in that indication. Still, last year management estimated that there were as many as 20,000 cystic fibrosis patients in the U.S., Europe, Australia, and Canada alone who could be taking its drugs and weren't doing so yet.  

There are also thousands of cystic fibrosis patients who don't benefit from CFTR modulators due to the nature of their underlying genetic mutation. Vertex has a drug candidate in the pipeline for that cohort of patients. It's currently enrolling participants for a phase one trial of the drug.

There's considerable growth opportunity for Vertex outside of the cystic fibrosis drug space, too. The company has multiple drug candidates in late-stage development, each of which represents a multibillion-dollar market opportunity in an indication where there are few or virtually no options for patients.

One treatment that could represent the most near-term commercial opportunity for Vertex is exa-cel, a gene-editing therapy that it co-developed with CRISPR Therapeutics. Exa-cel is currently under regulatory review. If approved, it would not only be the first CRISPR therapy ever approved, but also provide a functional cure for two rare blood diseases -- sickle cell disease and transfusion-dependent beta-thalassemia. 

Another Vertex candidate worth watching is VX-548, a drug designed to treat moderate to severe acute pain. CEO Reshma Kewalramani has described it as having "the promise of effective pain relief without the side effects or addictive properties of opioids." Bear in mind, the pain management therapeutic market is on track to reach a staggering annual valuation of more than $100 billion before the end of the decade.

Effective non-opioid treatments for acute pain certainly exist, but Vertex is looking to create a new class of drugs that could change the status quo with an option that isn't a scratch-the-surface treatment like over-the-counter painkillers are.  

Vertex Pharmaceuticals shares are up by about 23% year to date, a bit ahead of the S&P 500's increase of about 14%. The company raked in profits of $1.6 billion in the first half of 2023 alone. This healthcare stock bears watching, and for those with cash to invest, even a small piece of the pie could be well worth having now.  

2. Upstart

Lending platform Upstart (UPST 2.76%) has trounced the market's performance so far this year, a surge partly driven by short squeeze activity and partly by renewed interest in the stock amidst the artificial intelligence (AI) revolution. Even though the stock plunged after the company reported earnings in August, it's still trading up by more than 100% from the start of the year.

There were some improvements to note with its financials, and ongoing green flags for the business. There's also the fact that many of the struggles Upstart is currently contending with don't actually have to do so much with the underlying business itself as the macro environment it's currently operating in today.

Upstart's competitive advantage lies in its proprietary software, supported by AI and machine learning, which it uses to gauge consumer creditworthiness and approve or deny loan applications. In the past, Upstart has demonstrated that its software approves 173% more loans than banks using traditional FICO scores to assess would-be borrowers -- and with the same loss rate.

Given the challenging macroeconomic backdrop and the heightened risk of defaults that engenders, Upstart's software has approved fewer loans in the last several quarters than it did during prior periods.  Fewer consumers have applied for loans, too. And since the costs of funding them are higher, institutional investors have been buying fewer of Upstart's loans, so the company has had to carry more  of them on its own balance sheet.

This has caused revenue to drop, and the company isn't currently profitable. Still, the fact that Upstart's software is approving fewer loans is a testament to its ability to fine-tune its decisions to the environment at hand, not a sign of an internal deficiency. 

The company reached multiple long-term funding agreements earlier this year that should help it resolve its funding issues, too. It's also worth mentioning, to add more perspective to those funding concerns, that in the first half of 2023, 88% of loans funded through Upstart were either retained by the original lending partners or purchased by institutional investors. That means just 12% were carried on Upstart's balance sheet.  

Upstart reported revenue of $136 million in the second quarter of 2023, up 32% sequentially. It also narrowed its net loss from $129 million in Q1 2023 to $28 million in Q2. The company now has 100 banks and credit unions signed up to its platform (compared to just 10 when it went public a few years ago), and 87% of all loans processed through Upstart are now fully automated.  

These aren't the attributes of a dying business, and it's one of the few companies of its type and scale operating in the multitrillion-dollar lending industry. Upstart has work to do, but it still looks like it has a path to growth and profitability.