Facebook rose to its highest price in four months after an analyst at Sanford C. Bernstein & Co. said that investors have been underestimating its sales-growth potential.

Sales will be $6.98 billion next year and $8.65 billion in 2014, Carlos Kirjner, an analyst at Bernstein, projected in a research report yesterday.

The shares gained 8.1 percent to $25.94, the highest close since July 26. The stock has declined 32 percent since an initial public offering in May.