This is a text book perfect wave .
1. The move that started in Dec/2016 at 3060 ended at 4531. It was a five wave impulse move . channel technique says connect end of wave 1 and 2 and draw a parallel line from the top of wave 3 to get the end of wave 5 . In this case perfect channel has been seen . The other rule of the channel , which is not applicable here, if wave 3 is too steep then use the top of wave 1 .
2. a. A correction has to break the channel it is correcting
b. The correction will stop at the previous wave 4 of one lesser degree , especially if it is a wave 4 of one higher degree.
In this case waves 4 at one lesser degree is at 4150 but it does not break the channel convincingly . This is 23.6% Fib .
But the wave iv of the same degree at 3920 breaks the channel convincingly . This is 38.6 Fib.
3. The structure of the correction is still not complete.
Hence a short for atleast 4150 . Cover the shorts here . The stock is in a strong uptrend . Personally speaking dont short bull markets