Shares have soared in Shanghai but gave up a chunk of their initial gains as officials in Beijing outlined details of the government's stimulus plans. Hong Kong's Hang Seng sank nearly 6% as traders sold to lock in profits from recent gains. Shares elsewhere in Asia declined. On Monday, U.S. stocks slid after Treasury yields hit their highest levels since the summer. The S&P 500 fell 1% and the Dow Jones Industrial Average dropped 0.9% from its record set on Friday. The Nasdaq composite lost 1.2%. Crude oil prices added to their big gains from the prior week.