# Message Boards

GROUPS:
1 year ago
6 Replies
 Rick Jarosh 2 Votes Great post. It is possible to define copulas with higher degrees of asymmetry than the Clayton, Frank or Gumbel-Howard varieties by taking [Theta] in the normal copula to be a function of space rather than a constant: Attachments:
1 year ago
 Excellent post Jonathan. Looking forward to similar ones in the near future. I have a question regarding the calculation of the returns. For example, the S&P 500 on February 1, 2010 was 1089.19 and on the next day it increased to 1103.32 but when applying the original formula the log return is -0.0128895. Shouldn't the formula be reversed? Is my reasoning correct or am I missing something? Thanks in advance for the clarification.
1 year ago
 http://jonathankinlay.com/2017/01/copulas-risk-management/Copulas in Risk Management on Page 4 has: SP500returns = Log[Drop[SP500prices[[All, 2]], 1]] - Log[Drop[SP500prices[[All, 2]], -1]]; NASDAQreturns = Log[Drop[NASDAQprices[[All, 2]], 1]] - Log[Drop[NASDAQprices[[All, 2]], -1]]; Instead of (Drop -1) Minus (Drop 1)