Scam coins:

1) create a coin, the makers then buy it themselves at himself without investment, and as soon as the warrants for the purchase of sell all in one motion. Living example - BCC (bitconnect)
 
2) create a coin with a huge premine and the creators give all every week for 7% airdrop, and as soon as there is a serious warrant for the purchase of sell a huge balance in one motion. A living example - BTX