The bear market rally has been fueled by a flattening of the coronavirus curve in Europe and NYC, as well as continued monetary and fiscal stimulus measures. As we move past these two items into next week, the market will begin to shift its focus to the underlying fundamentals (GDP declines, unemployment, earnings, etc.) and how long it will take to get back to "normal". As investors realize the recovery won't be V-shaped, optimism will begin to fade.
Today, the S&P hit the 50% retracement level at ~$2,800 and formed an island top / doji reversal on the daily chart. However, we'll need to wait for confirmation Monday. If so, we'll be taking another leg down to re-test the lows in the coming weeks.