The value of insurance mergers and acquisitions may have grown tenfold, to $75 billion, during the bull market of the 1990s, but they barely created shareholder value. Market reactions to 237 insurance deals consummated in the United States and Europe from 1990 to 2001 show that acquirers beat the indexes, on average, by just 1.6 percent in the short term and 2.4 percent in the medium term. (Last year, the number of M&A deals in the sector returned to the more sedate levels of the early 1990s.) Some types of deals were more successful than others. Generally, investors liked acquisitions that helped companies to expand geographically or to market new product lines better than acquisitions intended to promote consolidation. They also favored deals that signaled focus, such as the buying and selling of divisions, rather than purchases of publicly listed companies with broad portfolios. And though many large bancassurance deals took place in the period, they received the thumbs-down: markets weren’t convinced that uniting two activities as different as insurance and banking creates value.