In general, penny stock investing is all about quick gains. Investors in this high-risk world usually are in it for a quick buck. Those who win tend to win big. Less often, investors buy penny stocks with a buy-and-hold mentality.

Buying and holding is precisely what we’re advocating for in this case. The companies and shares discussed below, if held for a few years, have all the potential to produce large returns for investors. The firms discussed benefits from trends that appear likely to continue to mature over the mid-term. In other words, a bit of patience and capital can turn into something much bigger.

Solid Power (SLDP)

Solid Power (NASDAQ:SLDP) will be a familiar name for many EV investors. The company is developing solid-state batteries with massive promise for the industry’s future. Solid electrolytes will produce a quantum leap forward regarding range and charging times. Range anxiety and charging times of several hours are massive barriers to wider EV adoption.

That’s where firms, including Solid Power, have such a massive opportunity. The race to develop and commercialize solid-state batteries will result in considerable spoils to the victor. Will Solid Power be the first to reach that goal? No one knows with any reliable degree of certainty. That’s the bet here, and it’s very straightforward.

 The positive news is that Solid Power has delivered a sample battery electrolyte to its partners, and the results remain promising. It is also on track to deliver sample cells to those partners this year. Further, Solid Power is in the revenue stages, proving that it is more than just a dream to produce tangible results.

CarParts.com (PRTS)

CarParts.com (NASDAQ:PRTS) does what its name says: It provides car parts in the U.S. and Philippines markets. In my estimation, 2 strong tailwinds in its favor should continue to strengthen over the next several years.

One, the average vehicle on the road in the U.S. is older than it’s ever been before. Light vehicles hit a record age of 12.5 years earlier in 2023. People are keeping their vehicles for longer. Of course, as a vehicle ages, so too do maintenance costs.

So, why is the average vehicle in the U.S. older than ever? The answer is straightforward: The economy isn’t strong overall, and consumers simply choose to hold onto their vehicles longer. However, I don’t believe that consumers will abandon their older vehicles even if the market becomes much stronger.

I hope that consumers are starting to see the value in running a vehicle for longer. More and more people recognize that vehicle payments are a massive hindrance to wealth accumulation in general. Driving an older vehicle can mean the difference between investing in your future and not. If my intuition is correct, that’s one more reason PRTS stock can explode upward in the coming years.

BioLine RX (BLRX)

BioLine RX (NASDAQ:BLRX) is an Israeli biotech firm with U.S. operations. The company has multiple FDA-approved treatments in its pipeline and more on the way potentially.

Bioline RX received FDA approval for APHEXDA for use in the collection of stem cells in the treatment of multiple myeloma. It is injected and allows most patients to reach a collection goal of more than 6 million hematopoietic stem cells. That improves stem cell transplantation, a standard treatment for multiple myeloma.

So, it is arguably the exact time to consider BLRX stock as it moves into the revenue production stages. The company is developing other drugs for commercialization in areas as diverse as sickle cell anemia and pancreatic cancer. Pancreatic cancer is a particularly lethal form of cancer that is often intractable because it is detected late in many cases. In short, BioLine RX offers immediate upside potential and longer-term upside due to the suite of drugs it continues to develop that address unmet needs.

On the date of publication, Alex Sirois did not have (either directly or indirectly) any positions in the securities mentioned in this article. The opinions expressed in this article are those of the writer, subject to the InvestorPlace.com Publishing Guidelines.