As a multimillionaire, O'Brien clearly has cash to invest and is entitled to spend his money how he chooses. But isn't it fascinating that he decided to buy a 3.1% stake in Independent?

O'Brien, who is deputy governor of the Bank of Ireland, does not have a major holding in any other Irish or British publicly-quoted firm. He has been highly critical of Independent Newspapers in the past and has accused the group's papers of making "outrageous attacks" on him. He has also complained regularly about other newspapers' coverage of his affairs, and has taken legal action against several papers.

One view is that by buying a stake in Independent, O'Brien may be hoping that its newspapers will give him softer coverage. Some likened the move to parking a small tank on Tony O'Reilly's lawn. Others rejected this as a plausible explanation, arguing that 56m was a lot to pay to stick two fingers up to somebody.

The O'Reilly family and other board members own about 28% of Independent, so O'Brien would have a hard job wresting control from that block, if that is part of his plan.

As yet he has not sought a meeting with management, and there has been no formal communication between the two sides other than a letter from O'Brien's lawyer advising Independent that he had acquired the 3.1% stake.

Whatever about his long-term strategy, O'Brien's interest in Independent helped push the share price up to a 12-month of 2.80 last week.