'Pump groups' fuel millions in trading activity, with price rises followed by quick falls.

If you are messing with cyptos in general, but especially the newer coin offerings, you are playing with coins rife with fraud.

The Wall Street Journal reports Traders Are Talking Up Cryptocurrencies, Then Dumping Them, Costing Other Millions.

Dozens of trading groups are manipulating the price of cryptocurrencies on some of the largest online exchanges, generating at least $825 million in trading activity over the past six months—and hundreds of millions in losses for those caught on the wrong side, according to a Wall Street Journal analysis.

In a review of trading data and online communications among traders between January and the end of July, the Journal identified 175 "pump and dump" schemes involving 121 different digital coins, which show a sudden rise in price and an equally sudden fall minutes later.