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by rah
April 30th, 2009, 12:36 am
Forum: Technical Forum
Topic: "Ultra" short type funds, how to price and hedge
Replies: 78
Views: 64299

"Ultra" short type funds, how to price and hedge

<t>QuoteOriginally posted by: daveangel.I am just not sure why T crops up though ?These funds can be statically replicated (in continuous time) by a portfolio of options that has an S^a payoff. That payoff has the unique property of being shape-invariant over time under the usual Black-Scholes assum...
by rah
March 7th, 2009, 6:18 am
Forum: Technical Forum
Topic: "Ultra" short type funds, how to price and hedge
Replies: 78
Views: 64299

"Ultra" short type funds, how to price and hedge

<t>Hmm, I seem to be having technical difficulties posting...With continuous rebalancing these funds would be producing an S^L payoff; an S^L payoff can be closely replicated with an appropriately weighted package of options of different strikes. So one way to understand these funds is just to think...
by rah
March 7th, 2009, 6:02 am
Forum: Technical Forum
Topic: "Ultra" short type funds, how to price and hedge
Replies: 78
Views: 64299

"Ultra" short type funds, how to price and hedge

QuoteOriginally posted by: PaulAny further thoughts on valuation and management of these instruments? I have received several emails recently which suggest to me that they are not well understood.P
by rah
February 22nd, 2009, 5:33 pm
Forum: Technical Forum
Topic: "Ultra" short type funds, how to price and hedge
Replies: 78
Views: 64299

"Ultra" short type funds, how to price and hedge

<t>QuoteThey seem to be quite different. Can you offer some more color on your statement?Consider a power payoff V = S^L. The instantaneous return dV/V on an investment in this is exactly L times the instantaneous return dS/S of the underlier. Change "instantaneous" to "daily" and you have the lever...
by rah
February 21st, 2009, 5:46 pm
Forum: Technical Forum
Topic: "Ultra" short type funds, how to price and hedge
Replies: 78
Views: 64299

"Ultra" short type funds, how to price and hedge

<t>The leveraged funds and ETFs are daily-balanced replications for derivatives with power payoffs like S^2, S^-2.With continuous replication the payoff over an interval T is (S(T)/S(0))^L exp(cT) where the carry c isL * q + (1-L) * r + L * (1-L) / 2 *sigma^2.Daily rebalancing just adds noise around...
by rah
February 5th, 2008, 3:49 pm
Forum: Technical Forum
Topic: Stochastic Volatility Models with Correlation Skew for Equity/FX
Replies: 9
Views: 62874

Stochastic Volatility Models with Correlation Skew for Equity/FX

<t>I think I need to expand on the calibration issue and how the historical variance swap data is used.The framework is a two factor model where the second factor is unobservable and controls instantaneous volatility, correlation, and potentially all the other process parameters. Since the second fa...
by rah
February 3rd, 2008, 7:53 pm
Forum: Technical Forum
Topic: Stochastic Volatility Models with Correlation Skew for Equity/FX
Replies: 9
Views: 62874

Stochastic Volatility Models with Correlation Skew for Equity/FX

<t>> But I wonder how you will be able to calibrate it. <The calibration is a very interesting problem. The calibrations in the paper are based on simultaneously fitting currently observed option prices plus historical variance swap prices. The latter carry a lot of information about volatility-of-v...
by rah
January 31st, 2008, 7:35 pm
Forum: Technical Forum
Topic: Stochastic Volatility Models with Correlation Skew for Equity/FX
Replies: 9
Views: 62874

Stochastic Volatility Models with Correlation Skew for Equity/FX

<t>Popular SV models (e.g. Heston) all seem to assume a constant correlation between the underlier and vol/variance even though both underlier vol and vol vol move around dramatically. This seems odd on the face of it, and also considering that most people would expect equity-equity correlation to r...
by rah
February 23rd, 2004, 9:50 pm
Forum: Technical Forum
Topic: skew and forward volatilities
Replies: 153
Views: 217546

skew and forward volatilities

<t>QuoteOriginally posted by: apineyes, you are correct that you should be quite sceptical especially on the close. however, the cboe provides delayed quotes throughout the day. so if you want, you can sample it as much as you wish. plus, you can always try to price the combos vs. the underlying quo...
by rah
February 23rd, 2004, 9:23 pm
Forum: Technical Forum
Topic: skew and forward volatilities
Replies: 153
Views: 217546

skew and forward volatilities

<t>QuoteOriginally posted by: apinewhy not use qqq and get the data from yahoo? if you want the options, get them from quote.cboe.com. this won't give historical option data, but it will provide some solution. or try the futures. it should not be too expensive to get sp500 futures data. or just do a...
by rah
February 23rd, 2004, 5:52 pm
Forum: Technical Forum
Topic: skew and forward volatilities
Replies: 153
Views: 217546

skew and forward volatilities

<t>There's a skew model I've wanted to look into for a long time but never had the time for before. The basic idea is that the instantaneous volatility should depend on S/A where A is a running average of S. You can throw in a stochastic contribution (independent of S) to A for good measure to lower...