That is a very very very good question Richhand. Thanks for the question.
If a signal occur even an hour before Asian open, you don’t take it. I understand there are times when price barely moved even when it enters Asian open, but still I strongly advice not to take it. Just wait for another signal. If a signal occur at the last hour of London open, though logically it will run through the US Session, you take it. For Fridays however, I will not enter any trades especially Secondary signals that is in the last 3-4 hours of London Open.
Why all this? Why can’t trade before Asian Open, why can’t trade after London Close, Why can’t trade at final hours of London Open?.. As I always say in tackling questions, it is all based on my experience and some statistical ‘evidence’ I’ve gathered after years trading.
Macfibo, like other trend-following systems, relies on trading range. Pre-asian market and post London market, based on what I’ve read and also based on my own logs/record… has the thinnest range compared to other sessions… that as one of the reason why I suggest not to trade Macfibo signals during the stated times. As to enter a trade that barely moved before Asian open inside Asian open, as in theory range will increase during this time, ugly reversals tend to happen as well… hence another reason why I advice not to trade any signals before Asian Open and after London close.
I hope my answers help.