Which is the best altcoin to invest upon in current month of Feb and upcoming month of March? 
no need to invest because of a bad market, just hold the coins you have and wait for the market to rise. Bad markets have been going on for a long time so don't try investing in this situation.
Best example for that is in the top of the list which is Ethereum. This altcoin proved not just its name but also its stability in the crypto market.