Figure: Voltage divider with capacitor
The standard voltage divider circuit that is discussed above faces a drawback - AC feedback caused through resistor RE reduces the gain. This can be prevented by placing a capacitor (CE) in parallel with RE, as displayed in circuit diagram.
This capacitor is generally selected to have a low enough reactance at the signal frequencies of interest such that RE is necessarily shorted at AC, so grounding the emitter. Hence feedback is only present at DC to stabilize the operating point, in which case any AC benefits of feedback are lost.
Certainly, this idea can be employed to shunt only a portion of RE, hence retaining some AC feedback.