115.13 to 115.9 is a relatively big shift for a single day's trading, but not a particularly big deal. There are plenty of days the Dow goes up or down 200 points or more, and then is right back where it started two or three days later.
Financial reporters just aren't very good at looking backwards beyond yesterday's trading. If stock X tumbled from $15 to $5 yesterday, but jumped from $5 to $6.25 today, they'll report on how "stock X was the number one gainer on the Dow today..."
Yes because you're looking at it from the yen's perspective. Now you can buy more dollars with the same amount of yen.