AMC Entertainment Holdings AMC.N was the biggest gainer in the Russell 2000, surging by 16.4% and extending the previous week's 85% gain. By Stephen Culp NEW YORK, June 7 (Reuters) - Wall Street started the week mixed on Monday as buyers stood on the sidelines on news of a global minimum corporate tax rate and lingering inflation fears, and a lack of market-moving catalysts. Lawmakers in Washington are doubling down on efforts to craft a bipartisan infrastructure spending package, with House Democrats expected to bring a bill to vote as early as Wednesday.