It's about testing the waters now but the idea is not to get too carried away. That is the line of thinking among buyers in pushing USD/JPY higher above the 155.00 mark currently. The pair finally breached the figure level in US trading yesterday but there is no major overshoot yet. Right now, it is trading around 155.45 - its highest level since 1990.

USDJPY D1 25-04
USD/JPY daily chart

From a technical perspective, the April 1990 high only comes in at 160.40. That is arguably the next key level on the charts to watch. At the same time, it seems like the line in the sand is shifting as Japanese authorities are alluding to the 160 mark as being a more critical one than at 155.

That being said, the pace of any decline in the yen is also a rather important factor in all of this. And that is also why USD/JPY buyers are being rather cautious to not overstep the boundary to trigger a reaction from Tokyo.

In any case, we're less than 24 hours until the BOJ policy decision tomorrow. That is going to be one to be mindful of, especially Ueda's press conference. The language that he uses is going to be heavily scrutinised and will surely be a make or break moment for the yen this week.

For now though, buyers are certainly dipping their toes in the water to see if the line in the sand has really shifted in USD/JPY. I reckon we'll only get confirmation on that tomorrow after the BOJ, and not before the market closes as well.