If you've had an eye on Wall Street for the past couple of years, you don't need me to tell you that markets can be unpredictable. In 2021, the major U.S. stock indexes soared, only to collapse in 2022. Now, they're on another upswing.

The growth-stock-heavy Nasdaq Composite Index recently booked its sixth-straight week of gains. While this could be the beginning of a much longer bull run, the market's thrown too many curve balls in recent years to safely assume stocks are going to keep moving in the right direction for very long.

Individual investor looking for stocks to buy.

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Markets can be highly unpredictable from year to year, but the long-term trend is clearly positive. Every market correction in history has been wiped away by subsequent recoveries.

Everyday investors can smooth out the bumps by making smaller, more frequent investments. Even $100 is more than enough to start or build a position in either of these terrific stocks.

If you have an extra $100 that you won't need to pay bills or cover unforeseen emergencies, putting it to work by purchasing the following stocks looks like a smart move.

SoFi Technologies

One of the best growth stocks investors can buy with $100 right now belongs to an increasingly popular consumer-focused bank called SoFi Technologies (SOFI 3.10%). This all-digital bank made its stock market debut about two years ago, and in that time, its membership base has expanded by 148%, to a whopping 5.7 million.

SoFi's financial services products, such as checking and savings accounts, are so popular that deposits rose by $2.7 billion during the first three months of 2023 to more than $10 billion. Most fintech start-ups need to partner with an actual bank to originate loans, but not SoFi. It obtained a national banking charter in early 2022 that allows it to fund new loans with member deposits.

Interest rates on lending products rose faster than the rates SoFi offers savers. As a result, the bank's first-quarter loss narrowed dramatically to $34 million from $110 million a year earlier, according to generally accepted accounting principles (GAAP). Management expects this trend to continue and has forecast positive earnings on a GAAP basis by the end of the year.

I liked SoFi stock a lot more last month when it was trading below its book value. The company is a member-based business that's growing by leaps and bounds, so investors who buy the stock at its recent price of around 1.4 times book value still have a strong chance to come out ahead over the long run.

Doximity

Doximity (DOCS 1.31%) operates a social media platform that's semi-exclusive to practicing healthcare professionals. With around 80% of U.S. physicians on the company's membership roster, pharmaceutical companies are beating a path to its door.

Doximity reported sales that rose 18% year over year during its fiscal fourth quarter that ended on March 31. This is slower than the company's typical pace but much faster than the advertising industry itself. During the same period, Meta Platforms reported average ad prices that declined 17% year over year and Alphabet reported Google advertising revenue that didn't grow at all.

Doximity doesn't allow members to post their own content in an attempt to gain attention. This way, the platform offers drugmakers and medical technology manufacturers a level of brand safety unheard of in the social media industry.

Doximity keeps physicians engaged with useful productivity tools. For example, last year, it acquired Amion, a service that manages more than 200,000 physician schedules at hospitals across the country.

Fiscal fourth-quarter revenue didn't rise as quickly as Doximity was expecting, and earnings contracted to $0.14 per share from $0.17 a year earlier. The stock is trading at around 42 times forward-looking earnings expectations, which is a huge multiple for a company with earnings that just shrank slightly.

As the only big social media platform for U.S. physicians, Doximity has a great chance to meet the stock market's lofty expectations. That said, investors who buy at recent prices could face swift and heavy losses if the company's bottom line doesn't start growing again over the next couple of quarters. Buying just $100 worth of the stock now, then revisiting it several months later, is probably the best course of action.