Tesla's (TSLA 1.85%) run-up of around 2,050% over the last three years made a lot of investors quite wealthy, but past performance doesn't predict future returns. And in the past 12 months, two small-cap biotechs have massively outperformed the world's most-memed-about electric car manufacturer.

What's more, these two companies aren't one-hit wonders that just got their first medicines approved -- and they're chasing cutting-edge projects. So if you're looking to park a spare $2,500 somewhere that it could grow, it's worth considering a purchase of one or both of these stocks. Here's why.

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1. Catalyst Pharmaceuticals

Catalyst Pharmaceuticals (CPRX -2.45%) is crushing Tesla stock because it's in the process of cornering a rare disease market that'll be worth hundreds of millions of dollars each year for quite some time. Its drug, Firdapse, treats adults with Lambert-Eaton Myasthenic Syndrome (LEMS), a muscle-weakening autoimmune and neuromuscular disease that affects around 3,000 people in the U.S.

In case you aren't familiar, rare diseases can be exceptionally lucrative targets for drug development, as businesses can often get privileged regulatory statuses that reduce their costs while also extending the exclusivity period of competition-free market penetration.

Right now, Catalyst is treating around 800 of those patients with its medicine, and it expects to be able to treat an additional 800 patients who have been diagnosed with LEMS already. As Firdapse is the only medicine that's approved to treat LEMS, the biotech currently holds around half of the addressable market in the U.S. (as determined by the number of patients who are correctly diagnosed with the disease), and there aren't any competitors or other barriers preventing it from capturing the other half in due time. That's good news for Catalyst.

This year, management expects to make between $195 million and $205 million from Firdapse, and its performance through Q2 suggests that's a very realistic goal. Assuming it hits the higher end of that range, its top line will grow by 45% year-over-year, which is quite rapid. It's also expanding into Japan and Canada, which will help to drive further growth through the rest of the decade. Plus, Catalyst is working to get Firdapse approved for pediatric patients, which would help to increase its addressable market too.

In sum, Catalyst is looking at a promising future, and that's why its shares are worth buying. 

2. Veru

Veru (VERU 0.39%) is another biotech stock that's easily beating Tesla, and it has two products instead of only one. There's Entadfi, its recently launched treatment for benign prostatic hyperplasia (BPH), and its prophylactic for women called FC2. Sales of these two interventions aren't exactly surging; in its fiscal Q3, the company only brought in $9.6 million in net revenue, down from $17.7 million a year prior. 

But there is an abundance of new opportunities that could yield big revenue, and soon. In June the company submitted an Emergency Use Application (EUA) to regulators at the Food and Drug Administration (FDA) for its drug sabizabulin, which it seeks to use to treat people hospitalized with COVID-19 who are at risk for severe outcomes. It's pursuing similar approvals in the E.U. and the U.K. Per its phase 3 clinical trial results, the medication could slash deaths in hospitalized patients by as much as 55%. If it gets approved, it could eventually treat as many as 250,000 patients per month, yielding tons of revenue in the process. 

But sabizabulin for severe COVID-19 isn't Veru's only program; it also has a pipeline with seven other late-stage clinical trials ongoing for applications in subtypes of breast cancer and prostate cancer. In the next three years, it's highly likely that at least one of those projects will make it to the market, supercharging its top line once again. With so many catalysts for its stock within view, there's a good chance that it'll continue to soar, and that makes it a great option for investment.