Biocentric Energy Holdings, Inc. (BEHL)

[el_loco09]

If I profitted lets say $40 on a different stock, sold it and invested it all in a losing stock, lets say, this one. Do I have to pay taxes on the stock I profitted on even though I lost it on this one if I am still holding this one?

Absolutely yes.

Or do I have to sell this one to offset the gains from the other?

Yes, you have to sell to realize the loss in the current tax year. Until you sell it's only a "paper loss". The same goes for gains. It's only recognized as a gain when you sell it to someone else.