How can a quant finance master's student in the US build American work experience before OPT or CPT eligibility begins?

You have more options than it feels like while you wait out the standard one year CPT clock, since on campus work and independent projects both count as real experience to a quant recruiter. Use your first two semesters to build technical proof through assistantships, open source contributions, and disciplined networking rather than sitting idle until eligibility kicks in.

Your Options Before Standard CPT Eligibility

Building Proof of Skill Without a Paycheck

• Register for an independent study under a faculty advisor and spend a semester backtesting a strategy or building a pricing library in C++.
• Contribute to open source quant libraries or compete on Kaggle, since merged pull requests and strong rankings give you concrete talking points in interviews.
• Check your program handbook for the immediate CPT exception, since a mandatory first term internship requirement can let your Designated School Official authorize CPT early.

My Advice

In your first week, email your department about research or teaching assistant openings and check your handbook for the mandatory internship exception, then spend evenings on one visible open source or Kaggle project so you have something concrete to discuss when quant recruiting opens in the fall.