What is the ruling on buying shares in a private hospital for speculative purposes, knowing that part of the hospital's funding came from usurious banks, and is the increase in the value of these shares considered usury?

There is no harm in purchasing shares from a hospital that was partially financed by a usurious bank, because not all of the money is illicit. The profits resulting from investing in these shares are lawful, with the advice to the questioner to avoid anything that involves the semblance of usury.