Solana Cuts Account Rent by 90% via SIMD-0437, Raising Value of Old Deposits

Solana's SIMD-0437 proposal, shipping with Agave 4.2, reduces the lamports-per-byte storage rate from 6,960 to 696 across five phased reductions, cutting the cost to open a standard token account from roughly 0.002 SOL to 0.0002 SOL. The change began rolling out on mainnet in late August 2026 and significantly lowers capital requirements for bulk account creation such as airdrops, which previously locked around 20 SOL for 10,000 recipients. Because the update is a relaxation rather than a forced adjustment, all accounts created before activation still return their original higher deposit when closed, making pre-activation accounts worth ten times more per close than new ones. This creates a finite, non-replenishing inventory of higher-value reclaimable SOL sitting in millions of empty token accounts, failed program deploy buffers, and leftover wrapped SOL accounts. Users and developers stand to recover meaningful SOL by closing these legacy accounts before they are forgotten entirely.