Learning the hard way by trading against it through the years, but mostly from UBS and their cycles!
Best is to go back and study historical charts (don't always follow the same pattern but more or less), other key factors includes earnings season months, ECB meeting dates, futures close-out, Santa rallies (triple witching), seasonal bearish/bullish months etc
Jan - Earning season month (first half bearish..second bullish)
Feb - Bullish but if Jan bullish followed by an uptrend then could be a top month (refer to previous years)
March - Bearish first half but futures close-out month so rally latter part
April - Earning season month (first half bearish..second bullish)
May - Tricky, sometimes bullish sometimes bearish but known as a very zig zag month
June - Mostly bearish but futures close-out month, after it is bullish...
July - Earning season month (first half bearish..second bullish)
August - Depend on bullmarket or bearmarket, if bull then bullish, if bear then bearish
September - Futures close-out month, first half bullish, second bearish
October - Earning season month (first half bearish..second bullish), also called month of bottoms
November - Bearish
December - First half bearish, latter bullish (Santa rally)
BUT...all of this must fit in with the tape, pattern and trend it is busy with!
Again, not set in stone but a good overall guideline!
good break-down analogy on market A...cant click the "like" button on your post unfortunately