Investor Group Boosts Share in ATI Medical

A Washington, D.C., investor group raised its stake in ATI Medical Inc. to 8.1% of the Glendale company’s stock from 5.2%.

In a filing with the Securities and Exchange Commission, Roxbury Partners and its two general partners, Christopher S. Middendorf and Jonathan Bowers, said they bought an additional 152,600 shares, giving them a total of 431,000 shares of ATI, which rents medical equipment to hospitals.

The latest stock was bought between Nov. 14 and Jan. 12, at prices ranging from $7.50 to $10.375 a share, the filing stated.