Buy here. Any sensible person (institutions) looking to buy after the last spike up would be waiting for the 200 SMA and a bigger retracement than simply the bottom of that triangle we were in. I certainly was. And now, it's at a more reasonable retracement, backed by the 200SMA, and I'm finally willing to buy after waiting a few agonising months.
The bearish perspective: breaking out of a triangle means many people will be looking to 'short the pull back'. So 9k-9.5k is now resistance. I could see it going down further, potentially to 7.2-7.5k, as that's a 61.8% retracement and significant support zone. Also, sentiment right now is extremely bullish, which is already priced in. Price moves with *change* in sentiment, so it's a question of whether people will get even more bullish from here, or more bearish. With bitcoin, I think there's more bearish potential. However, I'm less convinced by the bearish arguments than the bullish ones.
Many months ago, I made the decision to buy at the 200SMA, and the 50% and 61.8% retracement. Two of these have come at once.