Markets React to UkraineHeadlines about Ukraine were responsible for much of the movement in mortgage rates over the past week. Tensions rose ahead of the weekend and then the situation calmed on Monday. After all the volatility, mortgage rates ended the week with little change.On Friday, a quiet session was interrupted by reports that Ukrainians had destroyed part of an armed Russian convoy which had crossed the border into Ukraine. Investors reacted in the usual manner by shifting to safer assets, which was favorable for mortgage rates. The situation did not escalate, however, and Monday morning comments from Russian and Ukrainian officials indicated a willingness to discuss an agreement to end the fighting. Investors returned to riskier assets, erasing the improvement in mortgage rates.The housing data released this week showed nice improvement. July Housing Starts jumped 16% from June to the highest level since November. Building Permits, a leading indicator, also exceeded expectations. The August NAHB Housing Index showed that home builder confidence increased from 53 to 55, the highest level since January. Readings above 50 indicate that more builders view conditions as favorable than unfavorable.Looking ahead, investors will continue to watch the conflicts in Ukraine and other regions. The Jackson Hole monetary policy symposium will begin on Thursday. Speeches from Fed Chair Yellen and other global central bankers could influence mortgage rates. The next major economic reports will be Existing Home Sales and New Home Sales. After that, revisions to second quarter GDP will be released.