Andy was right in stating that most people aren't familiar with HPC, and it is indeed dominated by gov/university research. That being said there are people out there applying computational finance to these machines. I attended the Supercomputing Conference in New Orleans this year and sat in on the Computational Finance workshop which is going on its fourth year. I could try to find some email contacts I may still have from people I met there.
I did a small undergrad research project this past year in HPC in regards to finance. I found something I was interested in, the Longstaff-Schwartz MC method, and applied it to our schools cluster. I had the code in matlab, then I ported the matrix creation portion of it into C and ran that on the cluster. Granted I did not perform any groundbreaking, PHD level research, but it was a great way to show interest in comp. finance. My point being spend some time searching the web for some HPC related finance work...there is some out there. Find something interesting and apply it using MPI/OPENMP depending on your machine. Also if you would like the contacts just let me know. I believe I still have email addresses of a couple of the workshop directors.