5 Best Performing S&P 500 Stocks So Far in 2026

2. Teradyne Inc. (NASDAQ:TER)

Year-to-Date Performance: 105.39%

Teradyne Inc. (NASDAQ:TER) is one of the best performing S&P 500 stocks so far in 2026. On April 16, Teradyne acquired TestInsight, a prominent developer of semiconductor test validation and conversion software, to address the increasing complexity of AI and data center hardware. The acquisition is aimed at tightening the workflow between initial design and final testing, a process often slowed by the intricate requirements of modern silicon.

By integrating TestInsight’s virtual test and pattern generation tools with Teradyne’s automated test equipment/ATE platforms, the company intends to shorten debug cycles and accelerate the time to ramp for new AI devices. The value of this deal lies in pre-silicon validation. As product lifecycles for AI chips shrink, the ability to prepare and validate test programs before the physical silicon even arrives is a critical competitive advantage.

Teradyne CEO noted that these advanced software tools are now essential for customers to meet narrow market windows without sacrificing device quality. The integration is expected to yield a more seamless design-to-test environment that improves overall fault coverage and production reliability. Despite the merger, Teradyne Inc. (NASDAQ:TER) affirmed its commitment to an open ecosystem.

Teradyne Inc. (NASDAQ:TER) designs, develops, manufactures, and sells automated test systems and robotics products globally.