Clean energy stocks had a miserable 2023, as high interest rates and lingering pandemic-related supply-chain issues caused stocks of solar, wind, hydrogen and biofuels stocks to fall. This year, only six of the stocks in the 70-stock index have risen, and only four of those have market caps above $1 billion. The problem is that interest rates have stayed stubbornly high, so it’s still expensive to finance capital projects like wind turbines and solar arrays.