The public miners only sold between 20% and 40% of their bitcoin production from January to April this year, as most of them strived to keep the produced bitcoin as part of their "hodl-at-any-cost" strategy.
This strategy worked until the bitcoin price plunged from $40k to $30k in May. The bitcoin price decline spurred financial difficulties that forced the miners to start liquidating their precious bitcoin holdings, and May was the first month where they sold more than 100% of their production.
Many were shocked by the public miners' massive bitcoin sales in May, but in June, they sold about 14,600 bitcoin – almost four times as much as in May. The public miners only produced 3,900 bitcoin this month, meaning they sold almost 400% of their production, ultimately draining their bitcoin holdings by nearly 25%.