I didn't share this post on HN. I just wrote the article to summarize the ongoing story for my readers. This is a developing issue with new facts and explanati

I didn't share this post on HN. I just wrote the article to summarize the ongoing story for my readers. This is a developing issue with new facts and explanations coming out every day. For what it's worth, I am trying to explain the facts in this case. A new section has been added: > Clearing Houses & the Plumbing Behind Financial Markets > To be clear, there isn’t any hard evidence that Citadel directly influenced Robinhood’s decision to prevent users from purchasing GME shares. The CEO of Robinhood has denied any connection whatsoever. Instead, the decision has been attributed to clearing house requirements and “market settlement mechanics”. > This claim by Robinhood does appear to be valid. The Depository Trust & Clearing Corporation (DTCC) — a “clearing house” where shares are exchanged between buyers and sellers — is a core part of modern financial architecture, which serves to reduce risk to the system if one broker were to go bust. The DTCC requires members to post collateral. As trading volume and volatility grows, the collateral requirements also increase. > However, it looks like the DTCC increased margin requirements on GME stock on Thursday — which forced Robinhood to post more collateral — which drove Robinhood’s decision to prevent users from buying more GME shares. > This adds another piece to the puzzle. > We need more clarity on: Why did the DTCC make its decision? Was that decision properly communicated to the market, or did some firms get early access to the info? What conflicts of interest do they have? Was the DTCC lobbied by other Wall Street players to make that change on Thursday?