It is starting to get a bit draggy now as the headlines are persisting for more than an hour. But in any case, it’s not so much the confirmation of intervention that lessens the effectiveness. It is more so the fact that Tokyo is doing it against a backdrop that is not working in their favour i.e. lack of policy pivot by the BOJ, zero rates in Japan, US yields rising, Fed maybe not done with rate hikes, markets seeking shelter in general.
For now, Japan is trying to sell the idea that the threat of intervention is far greater to markets so that traders don’t push USD/JPY to test their limits.