Who And What Is Behind The After-Hours Performance Disconnect In US Stocks?

"Up until the end of March, there was little divergence [but] since April, all of the S&P 500 up move appears to have happened during extended market hours", JPMorgan's Nikolaos Panigirtzoglou writes, in the latest edition of the bank's popular "Flows & Liquidity" series. As shown in the figure (below), regular trading hours have, on average, served as a drag on US equities beginning just after the initial surge from the March panic lows. For some, this disparity is a source of conster