Investing in 2020 has certainly tested the resolve of long-term investors like nothing before. Even though we've witnessed stock market corrections and crashes, we'd never quite seen the broad-based S&P 500 lose 34% of its value in just a hair over one month.

But if there's one guarantee that never seems to let investors down, it's the idea that, eventually, bear markets and corrections will be firmly put into the rearview mirror by a bull market rally. This means each and every correction in history has been a buying opportunity, as long as you have a long investing horizon.

Another impressive attribute of investing in the stock market is that you don't need to have deep pockets to generate wealth. If you have even $100 that can be spared for investments and won't be needed to cover bills or emergencies, you have more-than-enough money to begin charting your path toward financial freedom.

Here are three of the best stocks you can invest in right now with $100.

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Image source: Getty Images.

Pinterest

There's good news if you missed your opportunity to get onboard the Facebook train before it left the station -- you're going to get a second chance with Pinterest (NYSE:PINS).

Pinterest may not yet have the ad-pricing power of Facebook, but it also hasn't run into the same growth constraints like a number of its peers. In the coronavirus disease 2019 (COVID-19)-affected second quarter, Pinterest delivered 39% monthly-active-user (MAU) growth from the prior-year period to 416 million MAU. This figure becomes even more impressive when you realize that over 90% of these net additions are from outside the United States. Although international users don't generate anywhere close to the same amount of revenue as U.S. users, this should give Pinterest plenty of opportunity to grow its average revenue per user and ad-pricing power throughout the decade.

Pinterest is also angling to become a leading e-commerce destination. Think about it this way: Its MAUs are willingly posting their interests and hobbies for the world to see. These are motivated people who Pinterest is logically connecting to small businesses that specialize in these interests and hobbies. Having already partnered with e-commerce platform-solutions provider Shopify, Pinterest is giving small businesses every possible opportunity to be successful.

I believe Pinterest could be worth more than $100 billion by 2030, up from its current valuation of $26 billion.

A person interacting with a seated bank teller from across the counter.

Image source: Getty Images.

Bank of America

Keeping in mind that patience is a virtue, buying into money-center giant Bank of America (NYSE:BAC) with your $100 could prove quite fruitful over the long run.

Over the next year or two, bank stocks will find growth challenging. They're not only contending with rising loan delinquencies, but also having their interest income-earning capacity limited by the Federal Reserve's ultra-dovish monetary policy.

However, Bank of America should be the prime beneficiary of a rebound in the U.S. economy. No big bank is more interest sensitive than BofA. With rates having nowhere to go but up from here, Bank of America should see a substantial increase in interest income by the midpoint of this decade.

Brian Moynihan has also done a bang-up job as CEO of the company. He's overseen a steady push to encourage digital and mobile transactions, while simultaneously closing some of BofA's physical branches. This has been an effective means of lowering noninterest expenses. Moynihan hasn't been shy about sharing the wealth, either. Prior to COVID-19 halting bank buybacks, BofA was set to return $37 billion to shareholders in a one-year stretch. The good news, though, is shareholders are still netting a better-than-3% dividend yield.

At 85% of its current book value, Bank of America represents a set-it-and-forget-it bargain in the financial sector.

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Image source: Getty Images.

Exelixis

Though investing in biotech stocks can often be an adventure, especially when most are losing lots of money, that's not the case for the highly profitable Exelixis (NASDAQ:EXEL).

Despite having a couple of approved therapies, the unquestioned lead drug here is Cabometyx. Exelixis' cancer drug is approved to treat first- and second-line renal cell carcinoma (RCC), as well as advanced hepatocellular carcinoma. Organic growth in these indications, along with increasing demand and solid pricing power, should give the company a pretty clear path to more than $1 billion in annual sales by 2021.

Just as important, Exelixis is running in the neighborhood of six-dozen clinical trials that are looking at Cabometyx as a monotherapy or combination therapy. Interestingly, the combination of Exelixis' lead drug with chief rival, Bristol Myers Squibb's immunotherapy Opdivo, has yielded highly promising results. The duo met its primary endpoint in late-stage studies for first-line RCC, and in more recently released data demonstrated a statistically significant reduction in death risk of 40% compared to prior RCC standard-of-care Sutent, which was developed by Pfizer. This combination therapy looks to have a good chance at being given the green light by the Food and Drug Administration, which'll further cement Exelixis' growth in the RCC indication. 

Ultimately, investors who buy Exelixis are getting a company capable of consistent double-digit growth and with more than $1.2 billion in cash on hand.