Assessing the Eruption

Biotechnology stocks erupted again this morning, with large cap biotech Biogen, seen below on a 15-minute timeframe leading the charge. As we all know by now, biotechs have been like a volcano erupting frequently for many years now.

At issue is whether one of these eruptions is an intermediate-term blow-off event, leading to a correction. 

In terms of assessing that issue, I am keying off Biogen. If we see a full gap-fill below (light blue line), either today or next week, it could easily mean that buyers are a bit exhausted up here, since in a true melt-up which lasts days or even weeks we would see gaps higher not get filled right away (leading much higher first for "exhaustion gaps" before eventually filling quickly).