Raymond James analyst Elliot Wilbur says shares of Impax Laboratories (IPXL) are up 20% after Shanghai Fosun Pharmaceutical disclosed this morning a 5.19% stake in the company. Investors interpreting the investment as strategic, setting up an eventual takeover of Impax, is inaccurate, Wilbur tells investors in a research note. The analyst points out that Shanghai Fosun has a New York-based investment arm with positions in companies including Valeant Pharmaceuticals (VRX), Dova Pharmaceuticals (DOVA) and Nature's Sunshine Products (NATR). The stake is just a passive investment made because the investment arm of Shanghai Fosun believes in the Impax turnaround story "and nothing more," Wilbur contends. He keeps a Market Perform rating on Impax. The stock in afternoon trading is up 20%, or $3.62, to $21.58.