Information Coeffecient and look ahead


In chapter 12 on the notebook 06_evaluate_trading_signals, IC (information coefficient which is calculated via spearmanr) is higher on lookahead 5 vs lookahead 1.

How is this possible?

Doesn’t this mean that the model is able to predict returns 5 days ahead better than 1 day ahead? What am i missing?

Thanks much for your help.