The 20 day is an interesting indicator. As seen marked by red arrows in the main chart above, each time it crosses the zero line indicating an increasingly negative over the past 20 bars, the market has experienced a greater wave of selling action to follow. This is usually preceded by a peaking of the positive increase in the before it turns around and begins to decrease as can be seen in early March.
The S&P 500 index has made significant gains since February rising almost 13% since lows.
Current price is less than 1% from the upper trend resistance line that goes back to August and November peaks in 2015. If it fails to break this resistance again we could see a return to support at 1800 which is down 12% from here. The risk/reward ratio at this point is rather unattractive. Here's a chart going back to 2014:
The percent of stocks that are trading above their 50 day moving average is unusually high at the moment. On average it's usually closer to 50% and during heavy period of selling it can drop below 30%. This statistic suggests traders should expect the market to be decline over the next few weeks. Here's a chart of this statistic:
In the next 2 weeks the next "earnings season" begins again. Analysts are expecting a drop in Y/Y of -7% Here's a good video clip from Nightly Business Report on this: