Pinnacle Shares Drop Most in Five Years on Deal With Synovus

Pinnacle Financial Partners Inc. shares plunged the most in more than five years after the bank agreed to combine with Synovus Financial Corp. in an all-stock transaction valued at $8.6 billion.

Some investors had expected both companies to draw acquisition interest from large regional banks, which would probably have resulted in more hefty premiums than a combination of two companies of similar size, according to Jeff Davis, managing director of financial advisory firm Mercer Capital.