BARCLAYS: Bond trading has undergone a fundamental shift

The business of trading corporate bonds has changed. 
The business is much less profitable than it once was.
More and more trading is being conducted through electronic channels, rather than by humans. There are fewer traders involved in the business and it is harder for investors to trade in and out of big positions.
And, trading has shifted away from principal trading — where banks take bonds on to their balance sheets for extended periods &md