CVA calculations
AAD
http://luca-capriotti.net/pdfs/Finance/jcf_capriotti_press_web.pdf
"least-squares" MC - Longstaff-Schwartz
2020 Savine-Huge Differential Machine Learning
https://www.risk.net/our-take/7691456/danske-quants-discover-speedier-way-to-crunch-xvas