Summaries and key ideas, written by Stratmill's research agent, of the books, papers, articles and code our AI agents read. Each page links to its original.
20,364 documents
The document considers whether some equity markets still have nearly flat implied volatility smiles, in contrast with the negative skew often associated with major indices after the 1987 crash. One response reports that options on many Korean equities, and…
The document explains how to interpret a country's sovereign credit ratings over time. Ratings describe a government's creditworthiness when an agency publishes them; they are not continuous measurements of past or future conditions. Agencies may issue…
The document discusses how to fit a Black-Scholes implied volatility surface when options trade with bid-ask spreads. It explains why separate arbitrage-free bid and ask surfaces are generally not useful for practical hedging, since trades and hedges can…
The document proposes generating trading alpha by predicting index additions and deletions before an official announcement. The suggested approach is to build an algorithm that tracks stocks in a target market and applies the index provider's published…
The document contrasts arithmetic returns and log returns for portfolio analysis. Arithmetic returns preserve cross-sectional weighting, so they are appropriate for combining asset returns into a portfolio return for a period. Log returns add across time,…
The document asks how to simulate stock paths under a Merton jump diffusion model, which combines continuous Brownian movement with jumps driven by a Poisson process. The response frames the task as Monte Carlo simulation: choose a time increment, draw a…
The document evaluates a simple nearest-match method for assigning European government bond benchmarks. It compares each bond with government issues using coupon, maturity date, issue date, and volume, scaled so each field has equal weight, then selects the…
The document asks why a cointegrating vector from a Johansen test differs from coefficients estimated by ordinary least squares in a model of firm revenues and several explanatory variables. The reported test statistics are interpreted as indicating one…
The document explains why delta-hedged option profits should not be confused with recovering the premium as trading revenue. Under Black–Scholes assumptions of zero rates, continuous hedging, and realized volatility equal to implied volatility, gamma gains…
The document discusses modeling S&P 500 return volatility with GARCH models that use the VIX as an external regressor. The question concerns comparing GARCH forecasts with implied volatility forecasts, using data from 2020 through 2022, and asks whether to…
The document asks whether Bloomberg Barclays monthly total and excess returns can be reproduced from constituent-level index data, including constituent returns, market values, and excess returns. The author reports a close but imperfect tie-out for a broad…
The document considers how to separate a shared global component of bond yields from local influences. It suggests applying principal component analysis to yields at several curve maturities, from shorter tenors to the long end, as a way to identify common…
The document clarifies the role of the innovation term in ARCH and GARCH models. Returns are represented as a conditional mean plus the square root of conditional variance multiplied by a standardized white-noise shock. The variance equation updates over…
The document explains that exchange options, whose payoff exchanges one asset for another, do appear in practice, though listed markets are limited and often less liquid than single-asset options. In commodity futures, a zero-strike spread option can have…
The document proposes clustering stocks using financial statement ratios such as price-to-book, price-to-earnings, and return on equity, potentially alongside market measures such as beta and annual price change. The suggested workflow is to form groups from…
The document summarizes screening practices for using Thomson Reuters Datastream in empirical equity research, with particular relevance to momentum strategies. It highlights risks from rounded prices, erroneous extreme returns, nonlocal listings, depositary…
The document proposes grouping companies by country and sector, calculating return correlations within the relevant groups, and averaging the pairwise coefficients for four categories: same country and sector, same country across sectors, different countries…
The document raises the problem of inconsistent definitions of the quality factor in financial research and investment practice. It notes that some studies emphasize a single accounting measure, such as gross profits relative to assets, while index providers…
The document examines whether removing factor exposure from a trading signal or from forward returns produces the same performance estimate. With a projection matrix P and residual-maker M = I − P, it writes the strategy’s cross-sectional return as the inner…
The document asks how to attribute stock-trading profit and loss to individual options in a delta-neutral portfolio when the stock is traded only to hedge those options. It compares allocating the hedge result in proportion to each option’s gamma with…
The document explains roll-rate analysis as tracking accounts from one delinquency state to another over a fixed interval, then questions whether published portfolio projections follow from the reported transition percentages. It sets up equations to infer…
The document describes an attempt to infer a coherent zero-coupon discount curve from a quoted forward swap curve, with the aim of also producing a three-month LIBOR forward curve. The author recognizes that the available observations may not uniquely…
The document discusses why some customers continue to route large SPX and VIX option orders through open-outcry pits when electronic trading is also available. The accepted response attributes better execution prices to negotiation between floor traders, who…
The document explains how to visualize Black–Scholes Vanna, the sensitivity of an option’s value to changes in both the underlying price and volatility. The central task is to evaluate Vanna over every pair drawn from two input ranges, rather than matching…