By Echo Wang NEW YORK (Reuters) – The U.S. Financial Industry Regulatory Authority (FINRA) warned on Thursday it was seeing a number of small initial public offerings (IPOs), including many from China, which constituted pump-and-dump schemes that investors should stay away from. Most of these initial public offerings raise less than $25 million for companies worth less than $100 million, FINRA said. Many of them involve Chinese companies and allocate as much as 90% of their offering to foreign broker dealers, primarily based in Hong Kong, limiting supply to artificially drive up share prices, …