Bitcoin dropped below $90,000 on Monday for the first time since April, touching an intraday low of $89,426 before closing near $91,200. The decline marked a more-than 20% retreat from the cryptocurrency’s October peak above $126,000 and has erased all of its gains for 2025. While broader market factors — including $2.3 billion of outflows from U.S. spot Bitcoin ETFs in the first half of November and rising Treasury yields — have contributed to the sell-off, an important supply-side pressure has come from Bitcoin miners themselves.…