Blind chart: real breakout or fakeout? Coin and date hidden, I'll post what happened tomorrow

Hourly chart of a real coin from a few weeks back, 3 days of it, scaled to start at 100 so the price doesn't give it away.

It ground higher for two days, then ripped about 15% in the last 12 hours on the biggest volume of the whole chart. Now it's stalling right under the high with a long wick.

Would you buy this breakout, sell it, or sit out for the next 12 hours? I'll reply tomorrow with what happened and which coin it was.