Check out the companies making headlines in midday trading: Generac Holdings -- Shares of the maker of power generators surged 8% as Hurricane Milton intensified into a Category 5 storm . Amazon -- The e-commerce stock lost 2.9% after Wells Fargo downgraded shares to equal weight from overweight and cut its price target, citing slowing growth and competition from Walmart. Pfizer -- Shares of the drugmaker gained nearly 3%. Citing sources families with the matter, CNBC reported that activist investor Starboard Value has amassed a nearly $1 billion stake as it pursues a turnaround at the company. Insurance stocks -- Property and casualty insurers saw shares under pressure as Hurricane Milton strengthened into a Category 5 storm with Florida preparing for evacuations. Allstate and Travelers both saw their shares fall more than 3%, along with Progressive and Chubb. These insurance companies have weather catastrophe exposure, so they could be exposed to potential insured losses tied to Hurricane Milton. Fort Lauderdale, Florida-based Universal Insurance plunged more than 15%. Air Products and Chemicals -- Shares of the industrial gas supplier popped nearly 8%. CNBC reported that Mantle Ridge has attained a stake in the company exceeding $1 billion, citing a person familiar with the matter. Garmin -- U.S. shares of the fitness device maker dropped 4.7% in the wake of a downgrade to underweight from equal weight by Morgan Stanley. The firm pointed to a deceleration in gro ...