This week could be the end of the multi-year rally. At least a test of the uptrend is near in the next days. A daily close below 17900 (pink line) would be a signal for the downtrend. Otherwise a break of the higher 18330 area (green line) would be a signal for a new uptrend.
Long-term key areas are 18130s-18140s as possible resistance zones and 16033-16074 as support area (yearly S1).
P.S. The chart was posted on Thursday, March 5, 2015 after the daily close of 18135.72. Next day the DOWI was down -1.54% (17,856.78) (-278.94)