You need USD to buy US stocks

What a run in the stock market.

Another record today has helped drive a bid in USD/JPY in the past few minutes. It touched 110.88 from 110.70 a short time ago. In Asia, the high was 110.98 as offers at the big figure weighed.

From where I stand, the miniscule bounce in USD/JPY is damning. Stocks have been on a relentless tear and Treasury yields have risen (although maybe not as much as you would expect) and still USD/JPY is languishing.

What happens when sentiment turns and -- God forbid -- the stock market has a negative day?