A very interesting summary graph from Factset on the impact of earnings performance relative to consensus expectations on share prices
In basic terms, upside to consensus is systemically rewarded, while downside impact decays over time. The chart reflects 5 years worth of data, so capturing the period of declining earnings, where positive surprises should naturally be priced at a premium. The question the data above raises is whether coincident or subsequent shares repurchases provide support to the upside for underperforming firms and/or for outperforming firms.
Remember, recent McKinsey research showed that deviations from consensus forecast do not matter that much when it comes to underwriting longer term returns: