At the start of February, SPX saw a number of "affirmations" that the uptrend was underway:
1. broke up and continued to trade above it's longer term trendline resistence
2. traded above its 200 day MA since 24th Jan
3. followed by a Golden Cross on 1st Feb
However the month of February began to see momentum evaporate as the index began to pullback below it's 20, then 50 days MA and finally stopped short at its 200 day moving average.
There are now a confluence of immediate "supports" coming up between 3920 to 3949, namely:
1. the 200day MA @ 3940
2. the long term trendline resistence that could have turned support
3. 38.2% fib retracement of the big AB upswing that began from Oct's low @ 3920
4. which is also the 61.8% fib retracement of the more recent BC swing
Therefore we need to see some rebound this week if the this pullback is just a breakup and retest of major prior resistences or something more bearish (which mean breaking below 3920).
A look on it's monthly chart showed that SPX had been mostly whipsawing within a wide sideway range of between 3585 to 4150 for the past 9-10 months and it is possible we could have more of that (think "STAGFLATION").
Hence unless we see some rebound this week or it could likely be a short term trader's arena right now (ie high volatility, short term swing ups and downs).
Can only wait and see.
Disclaimer: Just my 2 cents and not a trade advice. Kindly do your own due diligence and trade according to your own risk tolerance and don't forget that money management is important! Take care and Good Luck!