Eli Lilly has amassed a market value nearing a trillion dollars based on the assumption that demand for its new weight-loss medicine Zepbound will be virtually bottomless. On Thursday, the company’s startlingly disappointing third-quarter results are making investors ask themselves whether they had it wrong. Sales of Zepbound and Mounjaro, the name under which the same drug is sold to treat Type 2 diabetes, both fell well short of Wall Street estimates.