Amid a sluggish I.P.O. market, companies from China are finding a home in the United States. Last week, six Chinese stocks started trading on the New York Stock Exchange and Nasdaq, the most ever in a single week. The 35 Chinese offerings so far this year have accounted for 23 percent of I.P.O.’s in the United States, up from 1 percent in 2000, according to Thomson Reuters. More are expected in the coming months. Youku’s biggest rival, Tudou, filed plans last month to go public in the United States. For Chinese companies, listing on American exchanges comes with stricter accounting and disclosure standards—which can be costly for smaller companies just starting out.