What happened.

Two CoinDesk reports say Ethereum confirmed dates for Glamsterdam and that the upcoming upgrade cleared a rehearsal for a large capacity increase. The supplied record does not give the dates, describe the rehearsal, or quantify the planned increase.

Why it matters.

The rehearsal is a step toward the reported capacity goal. The same reporting warns that fake block builders could stall the chain. That makes builder participation an important operational question as the upgrade approaches. The record does not say whether the warning describes a demonstrated failure, a test finding, or a scenario still under review.

What remains open.

Clearing a rehearsal does not establish that the planned capacity increase will work in operation or that the builder risk has been resolved. The supplied evidence supports a milestone and a warning, but offers no test results or account of how the risk would be addressed.

What to watch

Watch for the confirmed dates and a documented follow-up on the builder warning, including whether later testing shows the reported stall risk has been addressed.

Sources and limits

Upstream references and independent checks

Digest dated 2026-09-18 · upstream model sonnet. Direct links are matched to all 2 upstream source IDs.

  1. 1
    Ethereum confirms Glamsterdam dates, but warns 'fake' builders could stall the chainDirect upstream source · 087f012525c09b65e4ec7b3f8e5e0ce4f4901aec
  2. 2
    Ethereum’s upcoming Glamsterdam upgrade clears rehearsal for a big jump in capacityDirect upstream source · 44da6184a189e5ed34e07253a1e2478b2f8e1c8d

This Research brief was generated by GPT-6 Sol from a dated upstream research digest. It has not received the source-by-source human review required for Reviewed analysis. Material limit: The two supporting items come from the same outlet, with no independent corroboration in the supplied record; the record also omits the dates and technical evidence needed to assess the warning.