The Plumbing: The $3 Billion Bill at 5am That Stopped GameStop Trading | Inside the Machine EP.10

January 28, 2021. 5:03am Eastern. Robinhood’s risk team receives a notification from the DTCC — the Depository Trust and Clearing Corporation. A collateral call. Amount: $3 billion. Required by: 9:30am. Robinhood has access to approximately $700 million.

At market open, GameStop buying was disabled. Not because of a conspiracy. Because the plumbing of financial markets sent a bill that could not be paid.

This is Episode 10 of Inside the Machine: How Markets Really Work — the final core episode before the Bonus finale.

What Is the DTCC?

The Depository Trust and Clearing Corporation settles approximately $2.15 quadrillion in transactions annually — more than ten times US annual GDP. Every US equity trade you have ever placed passed through their systems. They sit between every buyer and seller in the US equity market.

Through a process called novation, when a trade is confirmed, the DTCC inserts itself as the central counterparty to both sides. The buyer’s claim is now against the DTCC. The seller’s obligation is now to the DTCC. Your original counterparty is replaced by the clearinghouse. This substitution eliminates counterparty risk — you never need to worry whether the person who sold you shares will actually deliver them. The DTCC guarantees delivery even if the original seller fails.

To provide this guarantee, the DTCC collects collateral from clearing members — the brokers and institutions accessing its services. The collateral must be sufficient to cover settlement risk in stressed conditions. The riskier and more volatile the positions, the more collateral is required.

How Settlement Works: T+1

Under T+1 settlement rules — which the US adopted in May 2024 — equity trades settle the next business day. On the day of trade (T+0), the DTCC performs novation and your broker receives a margin requirement reflecting the settlement risk of your open position. On T+1, the seller delivers shares, your broker delivers cash, the DTCC facilitates the exchange, and your account is updated with the settled position.

Between execution and settlement, the DTCC holds the risk. The collateral requirement is calibrated to the size and volatility of open positions. A standard retail account has negligible collateral implications. Robinhood in January 2021 had a different situation entirely.

The GameStop Story: Resolved

By January 27, WallStreetBets had driven GameStop from approximately $20 to $350 in two weeks. Millions of Robinhood accounts held concentrated positions in the most volatile stock in US markets. On the evening of January 27 and into the early morning of January 28, the DTCC’s automated collateral model processed Robinhood’s aggregate customer position against observed volatility parameters. The output: $3 billion required by 9:30am.

Robinhood’s available liquid capital: approximately $700 million. The gap: $2.3 billion. Impossible to bridge in four hours through any available financing mechanism.

With two options — meet the collateral call or reduce the positions generating it — Robinhood restricted buying in GameStop and several other highly volatile stocks. The requirement dropped to approximately $1.4 billion, a gap bridged through emergency credit arrangements.

The popular conspiracy narrative — that Robinhood acted to protect Citadel Securities and its hedge fund connections — is emotionally coherent. The DTCC’s automated collateral model did not receive a phone call from a hedge fund. It ran a risk model. The restriction was forced by clearinghouse mathematics, not external pressure. Understanding what clearinghouses are and how collateral calls work makes this immediately obvious. Not understanding it produces conspiracy theories.

What This Means for Your Trading

Know the difference between cash and margin accounts in extreme events. A cash account trades only with settled funds and carries minimal clearinghouse collateral implications for your broker. In periods of extreme volatility, margin account restrictions are structurally more likely than cash account restrictions. Cash accounts trade flexibility for resilience during the conditions when flexibility is most tempting and most dangerous.

Understand T+1 and good faith violations. When you sell in a cash account, proceeds settle the next business day. Using unsettled proceeds to buy a new position and then selling before those proceeds settle constitutes a good faith violation. Three violations in twelve months can result in your account being restricted for 90 days. Knowing this prevents inadvertent violations at inopportune moments.

Position sizing that accounts for tail events. No individual Robinhood customer caused the $3 billion collateral call — the collective behaviour of millions of accounts created it. Maintaining broad diversification and position size limits protects not just against individual directional risk, but against scenarios where concentrated platform-wide behaviour triggers restrictions affecting every account including yours.

The Series Continues

Ten episodes. The market maker on the other side of every trade. The seventeen systems your order travels through. The dark pools handling 40% of volume invisibly. The PFOF business model funding zero commissions. The HFT arms race for microseconds. The circuit breakers that freeze your positions in minutes. The central bank transmission reaching every asset you hold. The liquidity that evaporates under stress. The passive flows reshaping price discovery on a calendar schedule. And the clearinghouse that sent a bill for $3 billion at 5am.

You now understand the machine. One more episode follows — the Bonus finale on AI trading and the autonomous algorithms increasingly making the decisions on the other side of every trade you place.

Frequently Asked Questions

What is a clearinghouse and what does it do?

A clearinghouse (central counterparty, or CCP) sits between buyers and sellers in financial markets. Through novation, it inserts itself as the counterparty to both sides of every trade — guaranteeing settlement even if the original counterparty fails. The DTCC is the primary US equity clearinghouse. CME Clearing handles US futures. Both collect collateral from clearing members to fund this guarantee.

What is T+1 settlement and how does it affect my trading?

T+1 settlement means equity trades in the US settle the next business day. For cash account holders, sale proceeds are technically unsettled until T+1. Using unsettled proceeds to buy a new position and selling that position before the original proceeds settle constitutes a good faith violation. Three violations in twelve months can result in account restrictions. Margin account holders typically have proceeds available immediately but are subject to margin requirements during volatility.

Why did Robinhood restrict GameStop trading?

Robinhood restricted GameStop buying primarily because they received a $3 billion collateral call from the DTCC at 5:03am on January 28, 2021. The call was generated by the DTCC’s automated risk model based on the size and volatility of Robinhood’s customers’ aggregate GameStop position. Unable to raise $2.3 billion in four hours, they restricted buying to reduce the collateral requirement. The restriction was a response to clearinghouse mechanics, not external pressure from hedge funds or market makers.

What is the difference between a cash account and a margin account?

A cash account allows trading only with settled funds. A margin account allows borrowing from your broker to trade larger positions, access to short selling, and typically immediate use of sale proceeds. The risk difference: margin accounts are subject to margin calls and are more likely to face restrictions during extreme volatility because the broker carries higher settlement risk to the clearinghouse on margin customers’ behalf.

What would happen if a clearinghouse failed?

The failure of a major clearinghouse would be among the most severe possible financial system events. CCPs are designed with layered protection: collateral from clearing members, a guarantee fund contributed to by all members, and the CCP’s own capital buffers. Regulators designate clearinghouses as systemically important financial market infrastructure and subject them to heightened oversight. This level of systemic failure has not occurred in modern financial markets.

As an Amazon Associate, Complete Trader’s Edge earns from qualifying purchases. Amazon links on this page are affiliate links.