Reporting season starts next week, and it ain’t going to be pretty.The tepid performance of the ASX 200 over the past 12 months has investors grumpy enough. But a repeat of the volatility of recent profit seasons – which have featured wild share price moves on relatively modest earnings surprises – looks certain, given the high level of disagreement between analysts on earnings outlooks, and growing prevalence of passive investing, algorithmic investing and so-called pod shops, which look to jump on earnings surprises.