About $100 Billion Vanished After My Technology Warnings Were Public

This is a story about investing, not home upgrades, but it touches on technologies sometimes pitched as part of the energy transition. An analyst who has spent years warning that certain clean-energy technologies were overhyped looked back at his own public warnings and compared them to what happened to company stock prices afterward. He found that companies in hydrogen fuel, electric air taxis (eVTOL), and small modular nuclear reactors (SMRs, compact factory-built reactors meant to be cheaper and faster to build than traditional ones) lost roughly $100 billion in combined stock market value after his warnings were already public. Hydrogen companies account for the largest share, about $59 billion, based on a 2020 warning that hydrogen faced high costs and competition from batteries and direct electrification. SMR developers Oklo, NuScale and Nano Nuclear have lost $30.3 billion since peaking in October 2025, with X-energy adding another $5.8 billion in losses.

None of this changes what rebates or tax credits are available for home upgrades like heat pumps, insulation, or weatherization (sealing up drafts and gaps in a house). Hydrogen, eVTOL aircraft and small nuclear reactors are not technologies homeowners install or buy into directly. The takeaway here is really about company valuations and investor risk, not about any change to home energy programs, equipment costs, or rebate eligibility.