I would characterize Tesla stock not as a pump & dump scheme anymore, but as a bet on Musk’s position to extract concessions from his political connections. He has got his way already with Trump planning to end EV subsidies that mostly benefited Tesla’s competitors, although Trump intended to do so anyway, and he may yet push against regulation that would threaten Tesla’s market position in the US, like federal charging standards. He may also get Trump to impose harsher tariffs on Chinese electrical vehicles than he otherwise would, although such tariffs enjoy bipartisan support.
Solar panels have indeed become cheaper and cheaper, and you are right to argue that the materials used to build solar panels are priced in. However, solar requires some infrastructure besides the panels themselves, such as inverters and storage, and that infrastructure needs additional materials, some of which are expensive. Copper, for instance, surged in price in 2020, and there is not enough investment to expand mining operations despite the great profits it has been yielding. This is an ongoing saga in the mining industry, with BHP attempting to take over Anglo American in part for its copper portfolio.
I am not arguing against solar; I just think it cannot be scaled to the extent necessary to cover most of our current and projected future electricity consumption. To get rid of fossil fuels and generate ever more electricity for EVs, the AI black hole and goddamn cryptocurrencies, I think we will need nuclear. I wish we would build more public transportation, break from the AI spell and ban cryptocurrencies, but I’m not hopeful. In any case, the pace solar has picked up these past years is very encouraging and we should do what we can to push it further.