Galaxy Research said in a report that the vast majority of Bitcoin rollups will be unsustainable. Bitcoin Rollups require millions of dollars per year to maintain due to transaction fees. "Each individual data release transaction can take up to 400KB (0.4MB) of block space, effectively taking up 10% of the entire block," Galaxy wrote. With multiple Rollups expected to release data every six to eight blocks, Rollups could quickly push base layer fees to new highs and make small transactions too expensive. Given the competition for block space, only Rollups that can generate the most fee revenue and pay for block fees will be able to sustain operations.