Citigroup has maintained a nearly perfect two year ascension channel (shown in red). I'm only showing the past seven years due to auto scaling issues from C's long term chart.
click on image to enlarge
While C also operates in a wider black line channel, you can see that the upper line of the blue channel is key and it just double topped at that line in the past three months and posted a shooting star on the second peak of the double top. This is not bullish.
Trade well my friends
Alan