S&P 500 monthly with some more interesting Fibonacci levels.

SP:SPX   S&P 500 Index
From the peak of the Bull market 2002 - 2007 I added 1.61%, this level was important in February 2018 when price was rejected for a time.

From the origin of wave 1 in 2009 to the top of wave 3 in 2015 I then added 61% to the top of wave 3 as shown in my last post titled :
S&P 500 weekly with some interesting Fibonacci levels.

I then used a fibonacci trend extension tool to add 61% of the distance travelled from the start of wave 1 to the end of wave 3 of this current wave which began in February 2016, the 61% was this time added from the low of wave 4.

Lastly I added a trend line connecting the tops of the 2002 - 2007 Bull market right through to the present day and then repeated this for the current Bull market from 2009.

I hope that by posting this chart along with my earlier posts you will now have a good idea of which levels/ trendlines to watch closely going forward.
As to what actions to take at these levels I will simple say listen to the market and it will surely tell you, good luck.
Comment: Hmm did we just witness a false breakout (exhaustion move) at the end of 2019 I wonder.