Alphabet (NASDAQ: GOOGL), the parent company of Google, has agreed to purchase nuclear-generated electricity from Constellation Energy (NASDAQ: CEG) under a landmark 15-year supply contract covering the utility’s existing nuclear power plants.

The agreement also includes a separate 20-year deal for Constellation to supply 890 megawatts of power from new nuclear facilities it will construct specifically to meet Alphabet’s future energy demands.

The long-term commitment from one of the world’s largest technology companies gives Constellation the financial confidence to invest $4.3 billion into new nuclear energy capacity, expanding an already substantial nuclear power portfolio.

Constellation shares rose sharply on the announcement, as investors responded to the scale and duration of the commitment from such a high-profile corporate buyer.

What caught many market watchers off guard, however, was the simultaneous rally in shares of small modular reactor developers Oklo (NYSE: OKLO) and NuScale (NYSE: SMR), two companies with no direct involvement in the Constellation-Alphabet agreement.

The surge in those stocks reflects a broader read-through that many investors appear to be drawing from the deal, one centered on the growing institutional acceptance of nuclear power as a serious long-term energy solution.

Unlike Constellation, whose typical nuclear facility is designed to serve hundreds of thousands of utility customers across a regional grid, Oklo and NuScale are pursuing an entirely different model for nuclear energy delivery.

Both companies are developing small-scale reactors intended to power individual industrial facilities such as refineries, smelters, and desalination plants, with the reactors built directly at the point of electricity consumption rather than feeding into a wider grid.

This decentralized approach positions small modular reactor developers as potential beneficiaries of the same underlying trend driving Constellation’s deal with Alphabet, namely the technology sector’s urgent and growing need for reliable, large-scale power that renewable energy sources have so far failed to fully deliver.

The commercial and industrial appetite for always-on power, free from the intermittency problems that have plagued wind and solar expansion, is increasingly pointing corporate energy buyers toward nuclear as the practical solution of choice.

As data centers, artificial intelligence infrastructure, and energy-intensive manufacturing operations continue to scale, the structural case for both traditional and modular nuclear power is gaining credibility among institutional investors and corporate planners alike.

The Alphabet-Constellation agreement, while specific in its terms, is being interpreted by the market as a broader validation of nuclear energy’s role in the future of American power generation.