Of course there was a strong selling reaction last time we hit 300. Lots of history there plus it is a psychological level. What happens next is what's important. Do we out of this and crash back down into the trading range, or march towards an ATH? Based on the recent "background" I'd say we have a great shot at breaching the supply area:
1) Stopping / selling climax in January
2) Test of supply at 220 succeeded (no sellers left down there)
3) Sideways, low consolidation period from April-June. Often signals the end of a trend.
4) Breakout of the 18 month bear trend followed by a rally to 315.
5) Increasing buy after the breakout.
This is a dangerous place to short IMO! Don't mess with this bull.