Story perspectives

Jane Street’s $15B July loss stems from margin calls

8/17/2026

Summary

Story summary

Jane Street lost about $15 billion in July 2026.
Jane Street’s $2.5 billion stake in AI hedge fund Situational Awareness fell 67 % in July, contributing to the loss.
Margin calls forced Situational Awareness to sell most of its public-equity portfolio to Citadel, whose head is Ken Griffin.
Jane Street generated over $40 billion in 2026 trading revenue, above 2025, and will close much of the risk and be more selective about risk.

History

Historical Context

In 1998, Long-Term Capital Management collapsed after a $4.6 billion loss, threatening global financial stability due to leveraged positions in emerging-market bonds. Founder John Meriwether and partners secured a $3.6 billion rescue package from the Federal Reserve, Merrill Lynch, Goldman Sachs, and other banks. Similarly, Jane Street’s July 2026 $15 billion loss, after a 67 % drop in its $2.5 billion hedge-fund stake, triggered margin calls and sales to Citadel. The 1998 crisis taught regulators to monitor leverage, prompting today’s tighter risk controls and selective exposure strategies at firms like Jane Street.

1 of 2

Story summary

Jane Street lost about $15 billion in July 2026.
Jane Street’s $2.5 billion stake in AI hedge fund Situational Awareness fell 67 % in July, contributing to the loss.
Margin calls forced Situational Awareness to sell most of its public-equity portfolio to Citadel, whose head is Ken Griffin.
Jane Street generated over $40 billion in 2026 trading revenue, above 2025, and will close much of the risk and be more selective about risk.

1 / 2