Luckily being compatible with Python 3 doesn’t mean replacing code wholesale, with it being possible to modify Python 2.6 code onwards to a form that is also compatible with a Python 3 interpreter.

The CPython interpreter in Python 3.14 can use a feature in C code that uses tail calls between functions. When compiled with a C compiler that supports these features, CPython runs slightly faster.

With 35 million lines of Python code, the Athena trading platform is at the core of JPMorgan's business operations. A late start to migrating to Python 3 could create a security risk.