Yesterday's rally was technically important for a few reasons.
1.) The SPYs closed above the 10, 20, and 50 day SMA. If prices continue to trade above the SMAs they will pull them up. This will increase the SMAs and will eventually give them an upward angle, which is a bullish indicator.
However, the 10 day SMA is below the 20 SMA and crossed below the 50 day SMA on Friday. The 20 day SMA is close to crossing below the 50 day SMA and will probably do so in the next few days. Both of these are considered negative indicators.
The MACD has decreased for the last two months and appears close to giving a buy signal over the next few trading days.
The CMF went positive yesterday, another bullish signal.
The SPYs came close to hitting the 38% fibonacci retracement in their latest sell-off. I'm not a strict fibnocacci guy; if the chart come close to a fib number it's usually good enough.