As I write this DXCM is up 3%, rising and $6.19. DXCM July 7.50 call options are cheap right here. Ask 25 cents and no bids. Compare to SPPI, currently at $5.81 and down over 3% today, the bid for 7.50 July is 40 cents and ask of 45 cents. SPPI stock trading volume is indeed much higher, but DXCM should be bid up if it continues to rise.
Yes, I'm happy too; I doubled down at $5.89 this morning before I left the house and just logged in at Starbucks to see it's back up. These under-$6 drops seem to be a good opportunity right now, I have to say I think this one is headed much higher. Having held through the painful route down to $3 and back, that's a relief (wish I had more confidence and added shares back then!)