Jill Goldsmith Co-Business EditorImax shares shot higher Wednesday as Goldman Sachs initiated coverage of the large-format leader with a “buy” rating, saying it’s well positioned to take share in the current environment and has ample cash to navigate a potentially turbulent recovery.The stock was up more than 16% on a day of solid gains for exhibition that saw Cinemark rising over 15% and Marcus up 13% with an hour left of trading.