Pump and dump schemes involve artificially inflating the price of a low-volume cryptocurrency through misleading information or fake hype. Scammers acquire a large number of cheap coins, spread false positive news, and encourage others to invest. Once the price reaches a peak, they sell their holdings, causing the value to plummet, leaving unsuspecting investors with significant losses. Be cautious of sudden market surges and do thorough research before investing in lesser-known cryptocurrencies.