19 Quotes by John Hull

"There are challenges in terms of the measurement of VAR for what are known as nonlinear derivatives, where things like gamma and vega are important dimensions of the risk."

"We started giving presentations at practitioner conferences in 1986, and since then all of our derivatives research has been stimulated by contact with practitioners."

"Yes, our tree has an interesting shape. The center branches reflect the shape of the zero curve. When extreme parts of the tree are reached the branching pattern changes to accommodate the mean reversion."

"The problem with interest rates are that you are not modeling a single number, you are modeling a whole term structure, so it is a sort of different type of problem."

"The real challenge was to model all the interest rates simultaneously, so you could value something that depended not only on the three-month interest rate, but on other interest rates as well."

"One important measurement issue concerns the fat tails problem that I mentioned earlier. VAR is concerned with extreme outcomes. If the tails of the probability distributions we are using are too thin, our VAR measures are likely to be too low."

"I didn't become interested in derivatives until 1982, 1983."

"When interest rates are high you want the average direction in which interest rates are moving to be downward; when interest rates are low you want the average direction to be upward."

"I think VAR is a very healthy development within the industry."

"Our starting point then was trying to find a way to incorporate mean reversion into the HoLee model."