BTC has an ascending trendline that goes back to the lows in October 2023, so I'd say this is pretty significant. It briefly fell below this trendline in early July, but quickly reclaimed until it broke again in early August. I'd be pretty careful here on either side honestly. I would like the long trade better honestly, if it does break out of this major bull flag once and for all, it'll almost surely lead to a new ATH and rally to 100k.
I'd rather take the long side on it, but I believe the short side has the higher probability. BTC is just not something I like to short often, plus I'm already short COIN. That was a huge break below that trendline and this is the first retest, I would expect at least a small rejection, but most likely a big one. If it can reclaim, I think the path to 100k is clear.