@The_DTCC should clarify what actions they took around increasing margin for the short squeeze names many brokerages restricted yesterday.

If they raised the margin brokers have to post on GME to 100%, it raises legitimate questions. Another natural question is regulatory role.

I tried to figure out what was happening yesterday but the size of capital @RobinhoodApp raised and the actions of other brokerages indicate that DTCC may have added specific margin add-ons for GME and other highly correlated stocks. https://twitter.com/KralcTrebor/status/1354952686165225478?s=20

They are permitted to do this under their publicly available and SEC approved rules governing collateral held at the Clearing Fund at NSCC.

The technical term is a Margin Liquidity Adjustment Charge.

Here's the source for the distrustful folks:

https://www.dtcc.com/-/media/Files/Downloads/legal/policy-and-compliance/NSCC_Disclosure_Framework.pdf

This would explain why other, very well-capitalized brokers would also restrict new buys in these names. It's simply uneconomic to allow customers to buy securities if the broker has to use its own capital to front 100% of the purchase for 2d.

If @The_DTCC did do this, and it's at least plausible to me that they did, then it really is the establishment shutting down this squeeze by using the plumbing to achieve an outcome they regard as desirable.

That's not the policy goal of regulated clearing and is problematic.