# All Questions

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### Is there a countably infinite Sigma-Algebra? Why?

Assume $\,\mathcal{F}$ be a nonempty collection of subsets of $\Omega$. $\,\mathcal{F}$ is called a $\sigma$-Algebra whenever if $A\in\mathcal{F}$ then $A^c\in\mathcal{F}$, and if ...
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### Individual investing as a quant [on hold]

Can one learn strategies that are applicable to personal/individual investing from a career as a quant?
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### compute technical indicators from candle data

i have a rookie question but can't find the answer anywhere so..what is the right way to compute a simple moving average when you have an array of (open,close,low,high) tuples ? From what i saw so ...
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### Ledoit-Wulf portfolio strategy calculation

I am trying to implement the Lediot-Wulf portfolio strategy on a real-world stock dataset. ...
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### Derivation of Stochastic Vol PDE

A couple questions regarding stochastic vol PDE derivation. Following Gatheral, a general stochastic vol model is given by \begin{align*} dS(t) & = \mu(t) S(t) dt + \sqrt{v(t)}S(t) dW_1, \\ dv(t) ...
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### Regression model when samples are small and not correlated

I received this question during an onsite interview for a quant job and I'm still scratching my head on how to solve this problem. Any help would be appreciated. Mr Quant thinks that there is a ...
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### Deriving the definition of stochastic integrals with respect to Ito processes from first principles

When I first encountered the definition of integrals with respect to Ito processes (Shreve's Stochastic Calculus for Finance Vol II), I didn't think twice. However, I wanted to see if the definition ...
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### Q regarding amortization of 500,000 loans

I am brand new to this forum. I asked this question on the main StackOverflow site and it was suggested that I ask here. My task is to find a method to quickly calculate the monthly cash flow on ...
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### How to get around flat likelihood function when calibrating GBM parameters

(Hope this is the correct place for this question - I posted it first on stackoverflow:) I want to calibrate jointly the drift mu and volatility sigma of a geometric brownian motion, ...
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### How to calculate implied volatility smile of basket using correlations?

For a basket, the realized volatility can be calculated using: $$\sqrt{\sigma_1^2 + \sigma_2^2 + 2 \sigma_1 \sigma_2 \rho}$$ If I have the volatility surface of two underlyings S1,S2 (strike space). ...
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### Derivation using Ito's Lemma of price process

define q(t) as the log price minus a linear trend $$q(t) = logP(t) - \mu t$$ assume teh log price process = Equation 1: $$dq(t) = - \Theta q(t) dt + \sigma dW(t)$$ Can you show that the ...