According to @TO, three new 4 MB “4 meggers” inscriptions just hit the Bitcoin network, with the first titled “Preserving history on Bitcoin” (source: @TO on X, Dec 11, 2025). A 4 MB inscription approaches Bitcoin’s 4,000,000 weight-unit block limit introduced with SegWit, meaning a single transaction can occupy most of a block and reduce concurrent throughput (source: Bitcoin Core documentation; Bitcoin.org Developer Guide). When large inscriptions consume blockspace, required feerates for timely confirmation tend to rise as the mempool grows, lifting on-chain transaction costs (source: Bitcoin.org Developer Guide; mempool.space fee estimation methodology). Traders should track real-time sat/vB fee tiers and mempool size to time on-chain moves during inscription waves (source: mempool.space explorer). Monitoring the share of miner revenue from fees offers a read on fee pressure during congestion (source: Blockchain.com Charts, Miners’ revenue from fees).