The time evolution of the polarization of the Si IIλ6355 Å absorption feature. Whereas some SNe Ia studied in Wang et al. (2007) were found to reach the largest Si II polarization roughly 5 days before the optical maximum, SN 2011fe clearly reaches the largest polarization after the optical maximum, if assuming a parabolic fit to the data with a shape similar to Wang et al. (2007; dashed line). Error bars were generated by determining the standard deviation of P_{Si II} estimations when q(ISP) and u(ISP) change according to the averages from Epochs 4–9, as shown in Figure 2. A continuum polarization level of ∼0.08% was not subtracted from P_{Si II}.