Oil prices are under pressure ahead of the next Federal Reserve meeting, with demand concerns continuing to weigh on both WTI and Brent.- The huge price volatility of the past couple of months has made European natural gas futures one of the favorite trading instruments of hedge funds as TTF futures continue to trade above €40 per MWh.- The combination of rapidly depleting European gas inventories and a still unclear outlook for Russian pipeline gas into Europe next year have lifted total long positions of institutional investors to almost…