"Pump and dump is a scheme that attempts to boost the price of a stock through recommendations based on false, misleading or greatly exaggerated statements." - Investopedia
Wikipedia also has some good information on the pump and dump scam and includes examples such as Stratton Oakmont, Enron and Langbar International. The page also includes comparisons with other types of schemes such as Ponzi schemes.
Statistics from www.coinmarketcap.com:
Jan 22 2018 00:02:00 UTC
$563,229,000 USD: Total Market Capitalization
$32,852,300,000 USD: 24-Hour Volume
34.37%: Bitcoin Dominance