Mega-cap energy stocks are not supposed to move this much. Tuesday’s first-quarter figures from BP and Shell – comfortably above consensus in both cases – sent the pair’s shares up about 6 per cent. Investors may have been waiting for an excuse to pile back in; BP had underperformed the sector by 13 per cent over the past 12 months and Shell had lagged behind by 8 per cent.

Is the rally justified? Earnings were boosted by forces beyond the duo’s control: average crude oil selling prices during the period were two-thirds higher than a year earlier, with gas about a quarter better. And there is nothing to alter the underlying story of structural decline. Shell’s crude oil output was down 6 per cent year on year while BP’s fell 2 per cent. At the oil sands division, Shell’s big hope – accounting for 3 per cent of earnings but 9 per cent of capital expenditure – net production fell by a quarter after mechanical setbacks. Glitches are becoming a habit for a unit that represents about a third of Shell’s proved reserves.