S&P Global buys OpenZeppelin after Kaiko deal

S&P Global agreed on Thursday to acquire OpenZeppelin, the open-source smart contract firm whose code runs beneath most major stablecoins. Neither company disclosed a purchase price. The deal came three days after S&P led a $110 million Series B top-up in Kaiko.

OpenZeppelin has published reusable smart contract building blocks since 2015. The company says its software has carried more than $37 trillion in value on blockchain networks. It has completed over 900 security reviews and reported finding more than 10,000 vulnerabilities.

In a company statement, OpenZeppelin chief executive Demian Brener wrote, “OpenZeppelin’s standards, technology, and expertise already power the infrastructure behind the world’s leading stablecoins, tokenized funds, DeFi protocols, and onchain markets.” Brener will remain chief executive and will report to Yann Le Pallec, president of S&P Global Ratings.

S&P has expanded its crypto work over the past year. The firm issued the first credit rating of a decentralized finance protocol, provided stability assessments for stablecoins, tokenized the S&P 500 with Centrifuge and created a hybrid crypto-equity benchmark. The OpenZeppelin purchase gives S&P a direct role in evaluating the code that moves tokenized money rather than only rating or analyzing crypto products.

Earlier in the week S&P led the $110 million top-up in Kaiko, a Paris-based data firm that sells pricing information across more than 150 exchanges and blockchain protocols. Investors in Kaiko’s round included BNP Paribas, Nasdaq Ventures and Royal Bank of Canada. Kaiko measures market prices while OpenZeppelin audits and supplies the contracts that execute transfers.

A study recorded 245 on-chain security incidents since January 2025 and reported that protocols that had passed independent reviews accounted for 88% of funds stolen in those breaches, totaling $3.63 billion through July 2026.

S&P’s entry into code ownership and security assessment takes place against a background of regulatory scrutiny. In 2015 S&P paid $1.375 billion to settle a Justice Department claim related to its mortgage ratings. Investors showed limited enthusiasm: S&P Global shares closed at $406.76 on Sept. 16, near the low end of a 52-week range that reached a high of $552.25. S&P and OpenZeppelin did not provide a timeline for integration or details on how OpenZeppelin’s products will be combined with S&P’s ratings and data businesses.