  Using electronic Raman spectroscopy, we report direct measurements of charge
nematic fluctuations in the tetragonal phase of strain-free
Ba(Fe$_{1-x}$Co$_{x})_{2}$As$_{2}$ single crystals. The strong enhancement of
the Raman response at low temperatures unveils an underlying charge nematic
state that extends to superconducting compositions and which has hitherto
remained unnoticed. Comparison between the extracted charge nematic
susceptibility and the elastic modulus allows us to disentangle the charge
contribution to the nematic instability, and to show that charge nematic
fluctuations are weakly coupled to the lattice.
