Butterfield Preferred dropped $10 (.81 percent) on the Bermuda Stock Exchange yesterday, trading three shares to close at $1,210.Butterfield Bank traded 95,660 shares to close at $1.22 without any change in share price.Overall, the BSX closed at 1,064.07, trading 95,660 shares worth BD$116,705.20 and three US shares worth $3,652.67