The most optimistic forecast I've seen recently is for Molecular Energies (MEN):
The one analyst offering a 12 month price target expects Molecular Energies PLC share price to rise to 820.47 in the next year from the last price of 77.50.
https://markets.ft.com/data/equities/te ... ?s=MEN:LSE
This would be a rise of 958.7% !