By Ben Aris in Berlin Gas prices have been falling fast in the last few weeks as the EU storage tanks are nearly full. Unlike equities, which are priced on a discount to future revenue flow, gas prices are set on the day depending on how much space is left in the tanks and how much gas is being consumed. Given at the moment the tanks are also completely full and thanks to one of the balmiest Octobers in years, the price for gas could well go negative in the next few weeks. “TTF spot gas prices fell to $990 per 1,000 cubic metres [€94.2/MWh] on high storage and warm weather in the region – the …