I also like sub 1$ stocks. If you like EXM you might like PRGN ~ others that I own or trade JAG, CXZ, SSN, URRE (out of these ATM) CPST has good base at 1$ MTG makes a nice CC candidate I tend to buy & keep buying if it goes lower & wait for a move up.
CHK is likely to break out above $20 before long provided there isn't a market correction during your contract's life. Consider a condor or iron condor.