I interned at HRT and SIG. Here's what it was like and what top quant trading firms look for in employees.

• Sarah Chieng is a former intern at Hudson River Trading and Susquehanna International Group. 
• She said a common myth is people think quant trading firms only recruit top school grads.
• Chieng also said that the firms care about your research and analytical skills.

This as-told-to essay is based on a conversation with Sarah Chieng, a 22-year-old former intern at Hudson River Trading, and Susquehanna International Group based in San Francisco. The following has been edited for length and clarity.