Graphics software developer Visio (VSIO) was upgraded by Bear Stearns analyst Peter Rogers to "buy" from "outperform."
The company's stock was up as high as 43-3/4 from yesterday's close of 41-1/4.
Bear Sterns said the rating change is based on the company's stock price, which dropped about 22 percent in the past week.
The company's stock was down more than seven percent from yesterday's close of 14.
Prudential attributed the rating change to Merdoch's acquisition of EchoStar.
Tel-Save upped to "strong
New Hope, Pennsylvania-based Tel-Save Holdings (TALK) was upgraded by Salomon Brothers to "strong buy" from "buy". The company's stock jumped as high as 19-1/2, about 45 percent, from yesterday's close of 13-1/8.
The upgrade follows Tel-Save's announcement that it will offer long distance telephone service to America Online members.
Salomon raised its 1998 earnings estimates to $1.40 a share from 75 cents a share and raised its 1998 revenue estimate to $900 million from $500 million.
Molecular upped to "strong
Laser-scanning, electro-optical, and software technology developer Molecular Dynamics (MDYN) was upgraded by Hambrecht & Quist analysts Rachel Leheny and Rob Olan to "strong buy" from "buy."
The company's stock was boosted almost 11 percent from yesterday's close of 13-1/8.
Yesterday, the company announced an agreement with Incyte Pharmaceuticals.
Reuters contributed to this report.