Jameson Lopp tackles the contentious topic of Bitcoin’s block size, proposing a Goldiblocks approach that’s neither too large nor too small. He examines how block space economics impact network security, discusses the failings of previous block size proposals, and suggests a dynamic algorithm that adjusts based on fee levels rather than arbitrary numbers. Lopp argues that technological advancement provides “free throughput” that Bitcoin should leverage, while ensuring blocks remain full enough to sustain a fee market that will eventually replace the block subsidy.
This presentation was recorded live at 2025’s OPNEXT, the Bitcoin scaling conference. For more info, visit opnext.dev. OPNEXT livestream and VODs are made possible by Taproot Wizards.
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# Notes:
– Blocks need to be full for a sustainable fee market
– Current fee market fluctuates between 1-10+ sats/vbyte
– Node performance improves ~15-20% per year
– Dynamic sizing needs 1000+ block adjustment periods
– Hard forks may be viable with 3-4 year lead time
– Block size should adapt to technological advances
