Throughout history, patient investors have been handsomely rewarded by the stock market. Since the beginning of 1980, the benchmark S&P 500 has navigated its way through five bear markets, yet has still managed an annualized total return of more than 11%. That's the power of buying stakes in great companies and trusting your investment thesis over many years.

Equally important is the fact that you don't need a mountain of cash to begin making money on Wall Street. With most online brokerages dropping minimum deposit requirements and commission fees, any amount of cash is suitable to begin or further your journey to financial freedom -- even $75.

If you have $75 ready to put to work in the market, which won't be needed for bills or emergencies, this is more than enough to buy some of the smartest stocks right now.

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Pinterest

To begin with, rapidly growing social media company Pinterest (NYSE:PINS) looks ripe for the picking.

A quick look at Pinterest's share price performance over the past two months might deter some folks. Pinterest has shed more than a quarter of its value after reporting a sequential decline of 24 million monthly active users (MAU) between the first and second quarter to 454 million. Wall Street had been counting on continued MAU growth. However, with vaccines rolling out in countries around the world, some users are spending less time online and perusing Pinterest.

However, thinking this MAU decline is a major concern would be a big mistake. The pandemic provided the perfect impetus for people stuck in their homes to engage online. Even with businesses and entertainment venues reopening, Pinterest's multiyear MAU growth remains well within historic norms. The 454 million MAUs the company ended with in June are nearly double the 231 million MAUs it had three years prior (in second-quarter 2018). 

The more important figure in the company's second-quarter operating results was its average revenue per user (ARPU). Despite a modest year-over-year increase of 38 million MAUs to 454 million in the second quarter, global ARPU soared 89%, with international ARPU up 163%. What this tells investors is that merchants are willing to pay up to reach Pinterest's large user base.

To build on this point, Pinterest's users are perhaps the most targeted of any social platform. Whereas most platforms have to do some proverbial poking and prodding to get the right ads in front of users, Pinterest's MAUs willingly post about the things, services, and places that interest them. With the legwork already done, all Pinterest needs to do is act as the middleman and connect merchants specializing in users' interests.

Long story short, Pinterest is still in the very early innings of monetizing its platform. International ARPU growth could reasonably sustain double-digit revenue increases throughout the decade. That should be music to investors' ears.

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Ping Identity

There is no shortage of trends that can deliver sustainable double-digit growth this decade, including cloud computing, marijuana, and electric vehicles, to name a few. But arguably the safest high-growth trend is cybersecurity. That's what makes Ping Identity (NYSE:PING) such a smart buy right now.

Over time, we've witnessed online and cloud-data security shift from being optional to mandatory for businesses of all sizes. Attacks are becoming more sophisticated, and the robots and people orchestrating these efforts don't take a day off just because we're in a pandemic. In fact, the pandemic has accelerated the shift of enterprise and consumer data into the cloud, which is placing even more emphasis on the need for cybersecurity solutions.

As its name gives away, Ping Identity specializes in identity verification solutions. Its cloud-based platform relies on artificial intelligence to grow smarter at recognizing and responding to potential threats over time. Ping's cloud platform is designed to help overcome the limitations of on-premises public and private cloud solutions by providing ongoing verification and risk assessment for users.

What's really exciting about this company is that we're seeing a growing emphasis placed on software-as-a-service (SaaS), as opposed to just term-based licensing. Even though term-based licensing is growing, subscription SaaS will generate higher margins and more consistent cash flow over the long run.

The June-ended quarter saw subscription SaaS sales up 51% from the prior-year period, albeit SaaS only accounted for 17% of total quarterly revenue. There's plenty of runway for subscription SaaS to become Ping's key growth driver.

What's more, we're finally beginning to see the company's double-digit annual recurring revenue (ARR) growth drive sales higher. Since subscription revenue is recognized over the life of a contract, growth in ARR and sales can be markedly different. ARR tends to be a more reflective measure of operating health for a company like Ping. With its gross margins consistently in the mid-80% range and ARR coming in between 15% and 19% over the past couple of quarters, now looks like the time to pounce for opportunistic investors.

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PubMatic

A final smart stock that investors with $75 can confidently scoop up right now is ad-tech company PubMatic (NASDAQ:PUBM).

Prior to computers and the internet, advertisers and publishers had to squabble over pricing and placement for every ad. It was time-consuming and inefficient. Thanks to the internet, all advertising is working its way toward becoming programmatic. Essentially, the buying, selling, and optimization of ads will be taken away from humans and placed into the proverbial hands of machine-learning algorithms.

PubMatic comes onto the scene as a sell-side platform within the programmatic ad industry. In simple terms, this means it works with publishers to sell their display space to advertisers. The company's cloud-based ad-tech infrastructure is designed to be incredibly transparent and allow publishers to control certain aspects of the selling process, such as inputting the minimum price they'd accept to sell their display space.

However, the platform also aims to maximize the value of impressions by placing ads that will be most valuable to a user and not necessarily the ad that would net the highest price. Keeping users happy and showing them relevant material is better for advertisers, which will ultimately drive display prices higher for publishers.

Clearly, PubMatic's approach is working, as evidenced by its dollar-base net retention rate of 150% in the second quarter. This figure tells us that the company's publishers using the platform in Q2 2020 spent 50% more in the most recent quarter.

According to PubMatic's management team, this company isn't even close to reaching its peak potential. Global digital ad spending is expected to grow by a compound annual rate of 10% through 2025, with mobile, video, and connected TV (CTV)/over-the-top (OTT) programmatic ads delivering respective annualized growth of 11%, 17%, and 11% through mid-decade. PubMatic's operating results have consistently doubled the industry's average growth rate, with CTV/OTT being PubMatic's fastest-growing segment.

Considering that PubMatic is profitable and growing rapidly, it looks to be a steal of a deal.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.