| 日期 | 代碼 | 券商 | 原評等→升級後評等 | 新目標價 |
| 2012/1/5 | NSC | UBS | Neutral >> Buy | $81 >> $92 |
| 2011/4/18 | NSC | BB&T Capital Mkts | Hold >> Buy | |
| 2010/9/27 | NSC | Avondale | Mkt Perform >> Mkt Outperform | $65 >> $70 |
| 2010/3/1 | NSC | Barclays Capital | Equal Weight >> Overweight | $55 >> $62 |
| 2009/9/3 | NSC | BMO Capital Markets | Market Perform >> Outperform | |