Just a couple of points. True, if one did sell at $7.50 and buy back at $3.50 one would be in a good position today. But this is looking into the past and making decisions in the present. And as we all know...
Hindsight is 20/20.
So the question is what do you do about those who sold at $1.25, watched it climb to $5.00 and bought. Then watched it fall to $3.50 and sold, then watched it climb to $7.50 and bought, then watched it fall... These are the stories we don't hear about.
Capital gains in US is taxed at 20% and applies if the stock has been held for more then one year. If you sell, then buy, then sell in a time period of less then a year, one will need to pay taxes at one regular rate.
I hope all your trades are profitable, but let me know when they are NOT as well and I'll be glad to commiserate with you!
Cheers,
BK