UEC
Uranium Energy Corp.
stock NYSEAMERICAN

You don't "immediately phase out" a working nuclear reactor, large or small, for a newer model. The high costs are largely up front, and fuel itself is only a small percentage of the cost to produce energy, much smaller than something like natural gas. Change usually only comes quickly in nuclear due to exogenous events (for example Fukushima for Japan's fleet). First movers in the SMR sector are likely (imo) to gain an enduring commercial advantage, lowering costs with economies of scale (the main draw of an SMR over a conventional large reactor) and being able to prove reliability to wary potential customers.
The ETFs are generally fine if you think sentiment for nuclear will become increasingly positive and result in continual net inflows. The weightings of all the major ones give me pause though because of the amount of overpriced junk held. HURA is 13% OKLO, 5% UEC, and even largest holding Cameco (a strong, resilient bear market company) is now trading at a PE over 120 with little exposure to rising uranium prices given their contract structures. I stock pick and stick to uranium producers because I have no real conviction in fuel services or reactor building sides.

I waited since 2020 for the nuclear boom to arrive, had UEC and UUUU. Sold when I was at a good profit early fall of 2025 but both have pretty much doubled since.