Datadog stock jumps 10% on tech company's inclusion in S&P 500 index

• Datadog shares were up 10% in extended trading on Wednesday after S&P Global said the monitoring software provider will replace Juniper Networks in the S&P 500 U.S. stock index.
• The addition of Datadog to the S&P 500 index follows the close of Hewlett Packard Enterprise's acquisition of Juniper Networks.
• Datadog is profitable, with a higher valuation than the median company on the Nasdaq Composite index.

Datadog shares were up 10% in extended trading on Wednesday after S&P Global said the monitoring software provider will replace Juniper Networks in the S&P 500 U.S. stock index.

S&P Global is making the change effective before the beginning of trading on July 9, according to a statement.

Computer server maker Hewlett Packard Enterprise, also a constituent of the index, said earlier on Wednesday that it had completed its acquisition of Juniper, which makes data center networking hardware. HPE disclosed in a filing that it paid $13.4 billion to Juniper shareholders.

Over the weekend, the two companies reached a settlement with the U.S. Justice Department, which had sued in opposition to the deal. As part of the settlement, HPE agreed to divest its global Instant On campus and branch business.

While tech already makes up an outsized portion of the S&P 500, the index has has been continuously lifting its exposure as the industry expands into more areas of society.

DoorDash was the latest tech company to join during the last rebalancing in March. Cloud software vendor Workday was added in December, and that was preceded earlier in 2024 with the additions of Palantir, Dell, CrowdStrike, GoDaddy and Super Micro Computer.

Stocks often rally when they're added to a major index, as fund managers need to rebalance their portfolios to reflect the changes.

New York-based Datadog went public in 2019. The company generated $24.6 million in net income on $761.6 million in revenue in the first quarter of 2025, according to a statement. Competitors include Cisco, which bought Splunk last year, as well as Elastic and cloud infrastructure providers such as Amazon and Microsoft.

Datadog has underperformed the broader tech sector so far this year. The stock was down 5.5% as of Wednesday's close, while the Nasdaq was up 5.6%. Still, with a market cap of $46.6 billion, Datadog's valuation is significantly higher than the median for that index.