Barclays' exit from energy trading stirs concerns over liquidity

British bank Barclays Plc has joined the list of top banks to exit energy trading, an exodus that analysts say raises concern among oil producers that falling liquidity means they cannot use derivatives for their basic function: to hedge risk by locking in future prices. Wall Street firms have scaled back in commodity markets since the 2008 financial crisis from owning physical assets or taking positions in the market in the face of regulatory scrutiny. The departure of Barclays exacerbates the