The financial services industry is famously complex, but that doesn't mean everyday investors can't put their money to work just like the professionals on Wall Street. In fact, the government makes it fairly easy.

The U.S. Securities and Exchange Commission makes institutional investors report their trading activity on Form 13-F every three months, and that information is publicly available. Whether you've been at it for decades or you're just getting started, studying the habits of the world's most successful investors could help you find top stocks to buy.

Investor on Wall Street.

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During the first three months of the year, billionaire money managers couldn't get enough of these stocks. Let's look at what's happened since the latest disclosures to see if everyday investors like us can get a better deal.

1. Palantir

In the first quarter, Cathie Wood, CEO of Ark Invest, bought 6.8 million shares of Palantir (PLTR -1.99%) for her firm's exchange-traded funds (ETFs). Since the end of March, the stock's risen 82%, and investors are probably right to wonder if it hasn't run too far already.

In a nutshell, Palantir helps governments and businesses analyze data from different sources that typically don't communicate. Its most well-known case studies involve cross-checking data from the FBI with various transportation departments to predict potential terrorist activity.

In its early days, Palantir was criticized for relying too heavily on government contracts, but that's changed. Now, commercial customers are responsible for a majority of total revenue.

Strong growth from both its commercial and government-facing operation allowed the company to post a $28 million net profit in the second quarter. The profit wasn't much, but it's a lot better than the $179 million loss the company reported a year earlier.

Demand for AI solutions is driving growth at Palantir, but the stock isn't cheap. It's currently trading for around 67 times forward-looking earnings estimates. If the market sees any sign of a slowdown in the quarters ahead, the stock's gains so far this year could all come crashing down. 

2. Uber Technologies

Now that it's no longer just a ride-hailing company, billionaire fund managers can't seem to get enough of Uber Technologies' (UBER -1.64%) stock. David Tepper and Appaloosa Management bought up 4.8 million shares of the mobility business in the first three months of 2023. That made it worth more than 10% of Appaloosa's total portfolio.

Tepper wasn't the only billionaire excited to buy Uber. James Simons and Renaissance Technologies grabbed 5.8 million shares in the first quarter, too. Both are likely pleased with their purchases. The stock has climbed about 40% since the end of March.

I'll be surprised if Tepper and Simons haven't added to or at least held on to their Uber shares. After years spent streamlining its business, the mobility company recently reported its first operating profit. Income from operations soared by $1 billion year over year to $326 million in the second quarter.

Uber also produced encouraging top-line results. Gross bookings grew 16% year over year in the second quarter, driven by mobility-segment bookings that climbed 25% higher.

On one hand, Uber looks like a reasonably valued growth stock to buy now. At recent prices, it trades for around 34.5 times forward-looking earnings estimates. That said, efforts to reclassify its drivers as employees instead of independent contractors could bring the stock crashing down.

In the state of California, Assembly Bill 5 extended employee classification status to gig workers, but Proposition 22 excluded Uber drivers when the state voted for it in 2020. Prop 22 has since been ruled unenforceable by a lower court, but that ruling was overturned by an appeals court this March.

This June, the California Supreme Court agreed to hear a challenge to Prop 22, but still hasn't set a date to do so. It might be best to keep this stock on a watch list until we can be sure Uber won't need to exit the state of California and additional states likely to follow suit if the challenge succeeds.