While Northern Trust's expected EPS of $1.21 sets a benchmark for performance, the stock's reaction will likely hinge on whether the company beats this estimate and provides strong future guidance. Historical data shows that even an earnings beat can be followed by a stock price drop, indicating that guidance may play a more significant role in investor reaction. The current bearish sentiment due to a 7.95% decline over the last year may temper any positive impact from an earnings beat unless accompanied by robust guidance.