Based on the wave count above, blue wave 'C' would move higher in 5 waves. The question is, does it take place from current levels or slightly lower levels? I don't have the answer to that but a break above the red ii-iv would give us a long signal. That line crosses near 1.5290.
If prices break to new lows before we break the red ii-iv line, I would shift the labels on the to the right meaning the resolution is similar, but starting from lower levels.
Notice how the Speculative Sentiment Index (S.S.I.) is getting progressively smaller on each dip lower. It has shrunk from +3.5 to + 2.5 to + 1.5 (approximately) on each dip. This is another undertone to the market and factored into the preference towards this being a 'B' wave.
Follow real time sentiment here to see if it grows more negative if prices push above the red resistance line.
On the other hand, an impulsive wave subdivides as 5-3-5-3-5 where the 4th wave does not overlap wave 1. The move from July 2014 to March 2015 is an impulse.
Another example of a diagonal is on the EURUSD intraday chart. From Nov 12 to Dec 3, it was an ending diagonal that appeared in the 5th wave position.
Let me know if you still have questions about it. Good luck!