Hard to know which stock is undervalued without doing proper fundamental valuation. Don't trust those do depend on technical valuation.. a lot of people have lost money trying to predict the future stock price looking at the past.
I would suggest you to get some valuation data using Factset/bloomberg or other database and do some Relative valuation and Free cash flow valuation using both equity approach and firm approach.

P.S dont forget to check the price using put-call parity either.. there might be arbitrage opportunity out there... i found one a month ago.. made a couple of thousand dollars. Could have made more if i had more to invest. :(