Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of Delaware trust bank Wilmington Trust (NYSE: WL) dove 44% in intraday trading as the bank announced that it's selling itself to M&T Bank (NYSE: MTB) for roughly $3.84 per share.

So what: Just last week I had my eye on Wilmington as investors considered the potential for a buyout. At that point I said, "true-blue investors had better make sure there's something other than a train at the other end of Wilmington's current tunnel." Looking at Wilmington's third-quarter results -- which were also released today -- it appears that it was, in fact, a train coming right at investors. The bank's total nonperforming assets jumped 77% since last quarter, and loan-loss provisions were boosted 37%.

Now what: It's been reported that the sale process for Wilmington included other potential acquirers and investors, including Bank of Montreal (NYSE: BMO), Toronto-Dominion Bank (NYSE: TD), and some private-equity players, so it seems relatively unlikely that a higher offer will come to the table for Wilmington. On the flip side of this massacre, it seems like this could be a positive for M&T shareholders. M&T will have its work cut out trying to get Wilmington's loan book under control, but will get $8.3 billion in deposits and a well-known name in the trust business.

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