Reddit is officially getting a seat at the big-kid table. S&P Dow Jones Indices announced on August 13 that Reddit Inc. will join the S&P 500, effective before the market opens on August 18, 2026.
The stock responded the way stocks tend to respond when they get invited to the most exclusive club in finance. Shares jumped as much as 11% in after-hours trading, a nice jolt for a company whose stock had been having a rough year, down 31.2% year-to-date before the announcement.
How Reddit got here
Reddit’s inclusion is technically an off-cycle addition, triggered by a corporate reshuffling elsewhere in the index. The pending acquisition of AvalonBay Communities by Equity Residential created a vacancy, and Reddit was next in line. Sun Communities will concurrently join the S&P MidCap 400 as part of the same reshuffling.
Speculation about Reddit’s potential index inclusion started as far back as 2025, when observers noted the company’s market cap and liquidity metrics looked favorable for the cut. Reddit was previously passed over during the 2026 quarterly rebalancing despite seemingly checking the boxes.
