Bermuda Commercial Bank dropped 50 cents (4.54 percent) on the Bermuda Stock Exchange yesterday, trading 200 shares to close at $10.50.Butterfield Bank traded 40,000 shares to close at $1.23 with no change in share price.Overall, the BSX closed at 1,068.60, down 3 points (.28 percent), trading 40,200 shares worth BD$51,300 and 2,132 US shares worth US$18,122.