The amount of data thrown investors' way can be overwhelming at times. Between earnings season -- the six-week period where most S&P 500-listed companies report their quarterly operating results -- and economic releases from the U.S. government, it can be tough to stay on top of Wall Street's market-moving events.
For example, investors might overlook the quarterly filing of Form 13Fs with the Securities and Exchange Commission, which is, arguably, right up there in importance with earnings and economic data releases.
A 13F is a required filing no later than 45 calendar days following the end to a quarter by institutional investors with at least $100 million in assets under management (AUM). This filing provides an under-the-hood look at which stocks Wall Street's brightest money managers purchased and sold in the latest quarter. Though 13Fs can paint a stale picture for very active hedge funds, they're usually insightful in the sense that they can help investors spot the stocks and trends piquing the interest of Wall Street's leading asset managers.
Image source: Getty Images.
Billionaire Warren Buffett is the stock market's most-famous and followed money manager -- but he's not the only billionaire known for his keen investing insights and ability to generate big profits. Investors also pay close attention to billionaire fund manager David Tepper of Appaloosa, who's overseeing north of $8 bullion in AUM, as of March 31.
What's made Tepper so popular has been his willingness to put his fund's capital to work in the high-growth tech stocks that have led the current bull market rally on Wall Street. But you might be surprised to learn that Appaloosa's billionaire chief has been a pretty persistent seller of three "Magnificent Seven" components over the previous year (March 31, 2024 – March 31, 2025), and an avid buyer of a double-digit growth stock with a burgeoning addressable market.
David Tepper is sending shares of three market leaders to the chopping block
Form 13Fs show that Tepper has cashed in his chips (partially or fully) on a number of high-growth tech stocks from the end of March 2024 to the close of March 2025. But the selling activity that stands out most has to do with members of the Magnificent Seven. Over 12 months, Tepper reduced his fund's positions in:
- Nvidia (NVDA +1.95%) by 93%, or 4,120,000 shares. (accounting for Nvidia's 10-for-1 stock split in June 2024)
- Meta Platforms (META +0.33%) by 51%, or 572,500 shares.
- Amazon (AMZN +2.16%) by 34%, or 1,318,000 shares.
NASDAQ: NVDA
Key Data Points
It's also worth mentioning that Tepper has cut his fund's position in Alphabet, specifically the Class C shares (GOOG), by 3%, as well as purchased put options on Apple.
To be fair, this selling activity in Nvidia, Meta Platforms, and Amazon might be nothing more than simple profit-taking. These companies have led the market higher, and Tepper has absolutely demonstrated a willingness to ring the register and lock in profits when the opportunity presents itself. The concern is there may be more to this selling than just profit-taking.
Perhaps the biggest worry is that Nvidia, Meta, and Amazon sport downside risk if an artificial intelligence (AI) bubble were to form and burst. Despite AI being the hottest trend on Wall Street since the advent of the internet roughly three decades ago, there hasn't been a next-big-thing innovation during this span that's avoided a bubble-bursting event. Investors consistently overshoot when it comes to early stage adoption and utility, and that'll likely be the case, yet again, with artificial intelligence.
NASDAQ: META
Key Data Points
The silver lining for Meta Platforms and Amazon is that their businesses were thriving well before the AI revolution. Meta brings in almost 98% of its net sales from advertising, while Amazon's rapidly growing cloud infrastructure service platform (Amazon Web Services), advertising services, and subscription services, would fare just fine if AI investments slowed. The same can't be said for Nvidia, whose AI-graphics processing units are the backbone of AI-accelerated data centers and the company's primary growth driver.
Appaloosa's billionaire chief may also have valuation concerns. While Meta and Amazon aren't valued at egregious multiples, Nvidia is tipping the scales at a trailing-12-month (TTM) price-to-sales (P/S) ratio above 26. That's more than double its peers and historically not a sustainable multiple.
Furthermore, the S&P 500's Shiller price-to-earnings (P/E) ratio entered 2025 at one of its priciest earnings multiple dating back 154 years. The five previous times the Shiller P/E has topped and sustained a multiple of 30 have, eventually, led to declines of 20% or more in Wall Street's major stock indexes. The Mag-7 stocks would likely endure significant selling pressure if the market rolls over.
Image source: Getty Images.
This is the stock billionaire David Tepper can't stop buying
However, Tepper has been doing some selective buying over the last year. Excluding options contracts, he's added 10 new positions to his fund and increased his stake in six other securities (stocks and exchange-traded funds, better known as ETFs).
None of these new purchases or additions stands out more than ride-sharing colossus Lyft (LYFT +0.76%). Between March 31, 2024 and March 31, 2025, Appaloosa's billionaire investor increased his stake by 8,532,382 shares, or 1,825%.
It's worth pointing out that while Lyft made up 1.3% of Appaloosa's invested assets at the end of March, chief ride-share rival Uber Technologies (UBER +1.02%) accounted for 2.8% of invested assets. In other words, this doesn't look to be Tepper choosing one company over the other. Rather, it appears to be a direct wager on rapid growth in ride-sharing.
As you might imagine, growth forecasts for the ride-sharing market are all over the map (pun fully intended). According to Stratis Research, the global ride-sharing market is projected to roughly 10X from an estimated $87.7 billion in sales in 2025 to a little north of $918 billion come 2033. This works out to a compound annual growth rate of 21% and is more than enough reason for Tepper to be excited about the two biggest players in ride-share space.
NASDAQ: LYFT
Key Data Points
But there are company-specific reasons Tepper chose to increase Appaloosa's stake in Lyft by more than 1,800% over the last year. One of those reasons is the company's much-improved key performance indicators. In the latest reported quarter (ended March 31), total rides climbed 16% to 218.4 million from the prior-year period, active riders jumped 11%, and gross bookings totaled $4.2 billion. In simple terms, Lyft is attracting more riders, and its active customers are using the service more frequently.
Arguably even more important than attracting new and return customers has been Lyft's operating cash flow. John Risher made it a point to improve the company's operating cash flow since taking over as CEO in April 2023. In two years, we've witnessed a complete 180, with Lyft now generating robust net cash from operations.
With Lyft decisively profitable and its cash flow rapidly expanding, it looks to be a much more attractive way to invest in the ride-sharing space than Uber Technologies. Mind you, Uber has a decisive market share lead, and with that typically comes some degree of valuation premium. But is Uber worth 4.3 times TTM sales while Lyft trades at a P/S ratio of just 1.1? Either Uber stock has gotten ahead of itself or Lyft is an attractive bargain.
Additionally, Lyft is leaning into digital advertising as a way to diversify its revenue stream and bolster its margins. Sponsorships that show up in maps or in "Sponsored Rides by Mode" offer a way for businesses to target users with their message(s), and for Lyft to put extra dollars in its coffers.
Though Lyft hasn't demonstrated its ability navigate an organic recession, it does bring an intriguing growth story to the table that's clearly piqued the interest of one of Wall Street's most-prominent billionaire money managers.
