Via a note from JP Morgan on the yen, analysts at the bank argue that a move above 160 raises the likely hood of further intervention by the BOJ.
JPM says that the BOJ rate hike we've seen so far is not tighter monetary policy (JPM have a point, the move from negative to zero is not 'tight').
JPM point out that the weaker yen is helping the BOJ quest for higher inflation. Which, of course, is true as far as it pushed up the price of imports.
Earlier, JPM had calculated that a yen depreciation would be positive for the stock market until 157 was hit. This, they said, is the break even point when expected pay rises would be cancelled out by inflation.
Yen update to kick off the week:
I've left the cursor hovering around 156.26, you can see the dashed line in the screenshot. I said last week this is an initial target, and I still think so.
After that there will be more work to do but we'll head to 158 next.