JPMorgan Chase cut back the financing it provided to Jane Street after the trading firm started making markets in US Treasuries and began competing directly with the bank.
In 2025, Jane Street traded more than $900 billion worth of bonds and generated around $40 billion in trading revenue almost as much as JPMorgan’s $41 billion from the same business.
JPMorgan reduced Jane Street’s credit lines to protect its own business.
It’s a simple pattern: When a client becomes big enough to threaten the profits of the company serving it, the relationship can quickly turn from partnership to competition. 
Source: https://www.ft.com/content/07e849ac-ea87-4227-81d4-7f18b0d7d473?syn-25a6b1a6=1
Bond guys can follow these steps in case they are out of their role.