নলেজ লাইব্রেরি

The document distinguishes dollar neutrality from market neutrality and addresses how to benchmark a dollar-neutral strategy with nonzero market beta. Equal dollar amounts on the long and short sides do not necessarily cancel market exposure. The response…

The document considers whether publishing a technical indicator can reduce its subsequent trading performance. It frames a strategy’s historical results as a mix of genuine alpha and overfitting, with only genuine alpha expected to persist out of sample;…

The document examines whether the sum of squared log returns is an unbiased estimate of variance under geometric Brownian motion. At finite sampling intervals, the estimate can reflect drift as well as volatility. The response explains why this convention…

The document explains whether the time intervals in a simple stochastic process can depend on the outcome ω. In the stated definition, the partition points are a fixed increasing sequence of times, while the process takes an outcome-dependent value on each…

This discussion considers whether commercial derivatives-pricing software will reduce the need for pricing quants. The responses describe a changing role: less development of entirely new pricing formulas in some settings, and more adaptation of existing…

The document asks how to validate a simple credit scoring system when a portfolio has no historical defaults or losses. The score is a weighted sum of borrower variables, with both variables and weights chosen through expert judgment. Since outcome-based…

This explanation examines the shift parameter in a lognormal model for forward interest rates. It writes a caplet payoff in terms of the shifted rate and strike, assumes the shifted forward follows a lognormal process under the appropriate forward measure,…

This document investigates inconsistent results when fitting a lognormal SABR volatility smile with pySABR. In the failing example, the fitted parameters produce volatility estimates that diverge sharply from the observed quotes when reused in another…

The note explains how collateral and funding payments relate to liquidation in perpetual futures. In the answer’s account, a position is liquidated when collateral falls below the maintenance margin. Collateral includes the amount initially posted, realized…

The note reframes the search for an equal-weighted basket of a fixed number of stocks with minimum volatility as a portfolio optimization problem rather than an ordinary knapsack problem. Portfolio variance depends on the full covariance matrix, including…

The note describes two ways to estimate implied volatility skew. One approach prices calls and puts across strikes, converts their prices to Black–Scholes implied volatilities, and estimates the smile’s slope. Another uses a call and a digital call at a…

The note explains that the Black model does not depend on the standard spot-to-forward relationship in which the forward price equals spot grown at the risk-free rate. Currency futures are given as an example where borrowing and lending in the two currencies…

The document discusses whether familiar time-series indicators such as MACD and RSI are useful as entry or exit signals in high-frequency trading. One response distinguishes visually interpreted technical analysis from quantitative finance, which generally…

The document explains how to project a mortgage’s expected cash flows when prepayment and default can end or alter scheduled payments. It favors using conditional event probabilities at each period, conditional on the loan remaining active up to that point.…

The document considers a process with Brownian diffusion and a time-dependent drift, then asks how to multiply it by an exponential factor so that the result is a martingale. The proposed approach applies Itô’s product rule to the process and the…

The document gives brief definitions of two terms encountered in derivatives pricing and volatility smile fitting. “Pillars” generally refers to maturities or expiry dates used as reference points, a usage associated with fixed income. A pricing or…

The document asks how the upfront amount for a credit default swap is determined and why the cash exchanged at settlement differs from the quoted principal amount. The questioner understands the principal as the difference between the present values of the…

The document explains why maximizing a portfolio’s expected return divided by its volatility leads to weights proportional to the inverse covariance matrix multiplied by expected returns. Because the Sharpe ratio is unchanged when all weights are scaled by…

The document explains why structured-product dealers may sell dividend exposure when equity markets fall. Products such as autocallable notes can leave dealers holding long-dated downside options or other exposures whose value and expected duration change…

The document asks whether the Basel–Vasicek unexpected-loss formula can be applied over a 20-year horizon, both to cumulative risk and to each year separately. It presents the formula in terms of loss given default, probability of default, asset correlation,…

The document examines why vega may give a misleading picture of volatility risk for options whose gamma changes sign, using a binary option as its example. Under Black–Scholes, it differentiates the discounted probability-based binary price with respect to…

The document explains the second stage of the Fama–MacBeth procedure after estimating each stock’s factor betas from a time-series regression. In each period, the cross-sectional regression uses that period’s returns across the stocks as dependent…

The document poses an instrument-selection problem: how to hedge an interest-rate differential sensitivity produced by a statistical model of spot FX returns on an intraday basis. The author seeks low trading costs and near-continuous availability, with an…

The document discusses when FX spot value dates roll and whether NZD pairs follow a different schedule. It presents competing explanations: one answer says NZD pairs roll at the Auckland market’s opening while most other pairs use the New York close; another…