The widely followed S&P 500 has hit dozens of new all-time closing highs in 2021. Since bottoming out during the initial wave of the coronavirus pandemic in March 2020, the benchmark index took just six months to make up the dramatic deficit it incurred at the start of the pandemic. Since then, it has gone on to gain another 36%. In short, from trough to peak, the S&P 500 has doubled in value in less than 18 months.

Yet the idea of putting money into stocks with the market constantly setting new records isn't appealing for some investors. But for those with a long-term mindset, there's no such thing as a bad time to buy into great businesses.

Close-up of one hundred dollar bill.

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Best of all, you don't need a lot of money to begin building wealth on Wall Street. Since most online brokerages have eliminated commissions and minimum-deposit requirements -- and many allow fractional-share purchases -- even a small amount of money can go a long way to getting in on great businesses.

If you have $100 at the ready not needed for bills or emergencies and a brokerage that allows fractional share purchases, you have enough to buy into the following pair of no-brainer stocks right now.

Person studying screen data.

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Palantir Technologies

Palantir Technologies (PLTR 2.88%) is the Liam Neeson of data analytics stocks: It has a very particular set of skills that were acquired over a very long career. It uses artificial intelligence to mine and identify patterns hidden deep within data sets. 

Originally offered to the U.S. government, its Gotham platform counts among its customers the FBI, CIA, NSA, and other government agencies, which use it to sift through and organize large amounts of data. The U.S. military is also a prime customer, using Palantir's technology to coordinate millions of troops around the world.

Yet Palantir realized that businesses also need to understand the vast bits of data they create every day, so it developed its enterprise-oriented Foundry platform to help streamline their operations by making big data easier to understand. Arguably, that's its future growth market.

It has grown its customer base from 125, at the time it filed its prospectus to go public last year, to 203 customers at the end of the third quarter, with the top three accounting for 18% of year-to-date revenue. Palantir's commercial customers grew 46% quarter over quarter, and its U.S. commercial revenue more than doubled from the year-ago period.

Because it has barely begun trying to reach new customers in new markets, Palantir has an enormous runway for additional expansion in the years to come. 

Wall Street expects revenue to triple by the middle of the decade, hitting over $3.3 billion, while earnings before interest, taxes, depreciation, and amortization is expected to surge from $443 million this year to $1.3 billion by 2025.

With few rivals who can do what it does, Palantir Technologies, at under $20 a share, seems a simple bargain stock to buy now.

Tesla Model Y being plugged in for a charge.

Image source: Tesla Motors.

Tesla Motors

It's not only the S&P 500 breaking through to new all-time highs -- Tesla Motors (TSLA 3.04%) has also delivered some eye-popping gains since the bottom last year, adding 990% to its valuation. 

Although the electric-vehicle (EV) maker has given back some of its biggest gains on fears about the Federal Reserve raising interest rates, Tesla continues to exceed expectations. It delivered a record 241,000 vehicles last quarter, almost all of which were its newer Model 3 and Model Y crossovers. This put Tesla within striking distance of delivering 850,000 vehicles this year.

With two new gigafactories in the works in Texas and Germany, the EV maker will be able to better meet demand here and abroad. Research firm Jato Dynamics reported Tesa's Model 3 was recently the top-selling vehicle on the continent. Those new facilities make it reasonable to believe Tesla could achieve 50% annual delivery growth over the next couple of years as more new gigafactories come online.

The third quarter also became Tesla's ninth-straight quarter of GAAP profitability. It's been able to maintain production amid the global supply-chain disruption because Tesla is every bit of a tech company as it is an automobile maker. With computer chips, in particular, in short supply, Tesla substituted alternative chips, rewrote the code, and inserted them into its vehicles to maintain production flow. 

One of the biggest concerns about Tesla has always been its valuation, with analysts debating whether it should be priced at half its current value or less. By either tech stock or automaker standards, its stock looks expensive based upon traditional metrics. However, with no peer able to achieve Tesla's combination of range, capacity, and power, it's the standard for the industry to beat.

It has rivals gunning for it, but Tesla looks like a no-brainer investment if you have $100 to put to work in the market right now.