What to do with Amgen (AMGN)?

Amgen reports earnings today after closing bell...

I've bought some shares of AMGN last friday because of a buy signal at my "daily-trading strategy".

Now my strategy will be either to sell the stock before the close today (if it gains some %) or to sell only half of my position and watch the performance of AMGN in after hour trading with an SL at 73,45.

Anyway - I will watch AMGN closely today...