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A.) Prices have broken the upward sloping trend line
B.) There is strong resistance in the upper 35/lower 36 area.
Let's look at the sell-off in more detail
A.) Prices gap down. This is a bearish development as it indicates a big change in the supply and demand picture favoring the bears.
B.). Prices print a strong downward bar, a gap, and then a second downard moving bar. This is a big development. There is also strong volume on these down days.
C.) The 10 day EMA is moving lower and has moved through the 200 day EMA. The 20 and 50 day EMA are also moving lower.