tl;dr
AppLovin and Robinhood Markets are set to join the S&P 500 index, effective September 22, causing their shares to rise 7% in extended trading. They will replace MarketAxess Holdings and Caesars Entertainment. The inclusion signifies growth and stability, prompting fund managers to adjust portfolio...
AppLovin and Robinhood Markets are celebrating a major milestone: both companies are set to join the S&P 500 index, sending their shares surging 7% in extended trading on Friday. The change, effective September 22, marks a significant step for the two tech firms, which will replace MarketAxess Holdings and Caesars Entertainment in the iconic index.
The S&P 500’s inclusion is no small feat. For investors, it’s a signal of growth and stability, while fund managers are required to adjust their portfolios to reflect the update—a move that often drives short-term demand for the newly added stocks. AppLovin, which specializes in mobile advertising technology, and Robinhood, the stock trading app beloved by retail investors, have both benefited from this news.
But the path to inclusion hasn’t been smooth. In March, short-seller Fuzzy Panda Research lobbied against AppLovin’s entry into the index. The company’s shares had already taken a hit in December when the S&P 500 committee chose Workday over AppLovin for a spot in the index. Meanwhile, Robinhood faced a similar setback in June when it was excluded from a quarterly rebalancing, causing its shares to dip 2%.
The S&P 500 already leans heavily toward big tech, with recent additions like Datadog and DoorDash. AppLovin’s inclusion adds another layer to this trend, reflecting the growing importance of digital advertising in the modern economy. The company’s stock has been on a rollercoaster ride, surging 278% in 2023 and over 700% in 2024. While its gains have slowed slightly in 2025—up 51% so far—the company remains a hot topic, especially after its bold move to acquire the U.S. TikTok business from ByteDance. That deal, however, has been delayed repeatedly by U.S. President Donald Trump, who has extended the deadline for the sale multiple times.
Robinhood, on the other hand, has carved out a unique niche as a platform for retail investors. Its role in the meme stock frenzy—where traders pushed up shares of AMC and GameStop—cemented its status as a household name. At its annual meeting in June, CEO Vlad Tenev was asked directly about the possibility of joining the S&P 500. “It’s a difficult thing to plan for,” he admitted, but added, “I think it’s one of those things that hopefully happens.”
The companies being replaced—MarketAxess and Caesars Entertainment—face a starkly different reality. MarketAxess, a fixed-income trading firm, has seen its shares fall 17% year to date, while Caesars, which operates casinos and hotels, is down 21%. Their exits from the index underscore the S&P 500’s evolving composition, favoring growth and innovation over traditional sectors.
For AppLovin and Robinhood, the S&P 500’s embrace is more than a symbolic win. It’s a vote of confidence from institutional investors, a boost to their visibility, and a potential catalyst for further growth. As the market continues to shift, these two companies are now part of a club that defines the heartbeat of the U.S. economy. Whether they’ll keep the momentum going remains to be seen—but for now, their shares are riding high.