When you buy/sell via an exchange, try to use limit orders (try not to use market orders). On some exchanges, like GDAX, limit orders have lower fees than market orders. On GDAX, limit orders are free as long as they don’t fill immediately. Meanwhile, market orders result in a .3% fee, which is better than the 1.4% that Coinbase charges but not as good as 0%, especially if you are day trading. If your exchange rewards you for using certain order types, aim to use them.
So far, everything we’ve discussed has involved taking a long position on a coin. That is, our focus has been buying a coin at a lower price than what we think we will be able to sell it at later. What if we have some indication that leads us to believe that the value of a coin is about to decrease? In this case, we could take a short position, which is the same technique that made some people boatloads of money during the 2008-2009 housing bubble.
Identifying stop loss levels to minimize losses:  In the order book we identify the points of support that we also analyzed before. It is likely that being supportive, massive demand (a “wall” of buyers) is present around those spots. This is the best zone to place the stop loss command, although it should be placed a little lower than the high demand zone. They will only get to our command if the sellers manage to lower the price and the “wall” of buyers breaks. The “wall” of buyers works as a sort of protection level for our command.

Always pay attention to Bitcoin. Most altcoins (every cryptocurrency except Bitcoin) are pegged more closely to Bitcoin than Asian currencies were to the USD during the Asian Financial Crisis. If Bitcoin price pump drastically, altcoins price can go down as people try to exit altcoins to ride the BTC profits; inversely, if Bitcoin prices dump drastically, altcoin prices can go down, too, as people exit altcoins to exchange back into fiat. The best times for altcoin growth appear when Bitcoin shows organic growth or decline, or remains stagnant in price.