William Blair analyst Sharon Zackfia says that after raising her Q3 CarMax used unit comp estimate to 4.5% on web-scraping data through October 20, trends have subsequently not accelerated as quickly as she had anticipated against easier comparisons over the past three weeks. The analyst's web-scraping data through November 10 now suggest a used unit comp in the range of 0% to 2%. While this is worse than consensus expectations of 3.5% to 4.0%, such a result would be better than widely feared expectations that comps could retract into negative territory this quarter, Zackfia tells investors in a research note. She lowered her Q3 comp estimate for CarMax to 0.5%-1.0% and earnings per share estimate to $1.00 from $1.05, just below the consensus at $1.02. Zackfia keeps an Outperform rating on the shares.