Thanks for detailed explanations!

Actually I started a small position to practice this strategy yesterday, which qualifies as a sort of "an intermediate top in a confirmed uptrend" entry point somehow.

I did notice that when market moves quickly to lower BE (790), you used a call calendar to compensate Vega, i'm wondering if a put calendar would makes more sense since market trend was primary down at that time?

Thanks again for all the sharing.

PX